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Index

MDN JavaScript pages

This page lists all MDN JavaScript pages along with their summary and tags.

Found 695 pages:

# Page Tags and summary
1 JavaScript JavaScript, Landing
JavaScript® (often shortened to JS) is a lightweight, interpreted, object-oriented language with first-class functions, most known as the scripting language for Web pages, but used in many non-browser environments as well such as node.js or Apache CouchDB. It is a prototype-based, multi-paradigm scripting language that is dynamic, and supports object-oriented, imperative, and functional programming styles. Read more about JavaScript.
2 A re-introduction to JavaScript (JS tutorial) Intermediate, JavaScript, Tutorial
Why a re-introduction? Because JavaScript is notorious for being the world's most misunderstood programming language. While it is often derided as a toy, beneath its deceptive simplicity lie some powerful language features. JavaScript is now used by an incredible number of high-profile applications, showing that deeper knowledge of this technology is an important skill for any web or mobile developer.
3 About JavaScript Beginner, Introduction, JavaScript, beginner
JavaScript® (often shortened to JS) is a lightweight, interpreted, object-oriented language with first-class functions, and is best known as the scripting language for Web pages, but it's used in many non-browser environments as well. It is a prototype-based, multi-paradigm scripting language that is dynamic, and supports object-oriented, imperative, and functional programming styles.
4 Closures Closure, Intermediate, JavaScript
Closures are functions that refer to independent (free) variables. In other words, the function defined in the closure 'remembers' the environment in which it was created.
5 Concurrency model and Event Loop Advanced, JavaScript
JavaScript has a concurrency model based on an "event loop". This model is quite different than the model in other languages like C or Java.
6 Enumerability and ownership of properties JavaScript
Enumerable properties are those which can be iterated by a for..in loop. Ownership of properties is determined by whether the property belongs to the object directly and not to its prototype chain. Properties of an object can also be retrieved in total. There are a number of built-in means of detecting, iterating/enumerating, and retrieving object properties, with the chart showing which are available. Some sample code follows which demonstrates how to obtain the missing categories.
7 Equality comparisons and sameness Comparison, Equality, Intermediate, JavaScript, Sameness, equality
Briefly, double equals will perform a type conversion when comparing two things; triple equals will do the same comparison without type conversion (by simply always returning false if the types differ); and Object.is will behave the same way as triple equals, but with special handling for NaN and -0 and +0 so that the last two are not said to be the same, while Object.is(NaN, NaN) will be true. (Comparing NaN with NaN ordinarily—i.e., using either double equals or triple equals—evaluates to false, because IEEE 754 says so.) Do note that the distinction between these all have to do with their handling of primitives; none of them compares whether the parameters are conceptually similar in structure. For any non-primitive objects x and y which have the same structure but are distinct objects themselves, all of the above forms will evaluate to false.
8 Index JavaScript, MDN, meta
This page lists all MDN JavaScript pages along with their summary and tags.
9 Inheritance and the prototype chain Inheritance, Intermediate, JavaScript, OOP
JavaScript is a bit confusing for developers experienced in class-based languages (like Java or C++), as it is dynamic and does not provide a class implementation per se (the class keyword is introduced in ES6, but is syntactical sugar, JavaScript will remain prototype-based).
10 Introduction to Object-Oriented JavaScript Constructor, Encapsulation, Inheritance, Intermediate, JavaScript, Members, Namespace, OOP, Object, Object-Oriented
Object-oriented to the core, JavaScript features powerful, flexible OOP capabilities. This article starts with an introduction to object-oriented programming, then reviews the JavaScript object model, and finally demonstrates concepts of object-oriented programming in JavaScript.
11 JavaScript Guide Guide, JavaScript, guide, l10n:priority
The JavaScript Guide shows you how to use JavaScript and gives an overview of the language. If you want to get started with JavaScript or programming in general, consult the articles in the learning area. If you need exhaustive information about a language feature, have a look at the JavaScript reference.
12 Control flow and error handling Beginner, Guide, JavaScript
JavaScript supports a compact set of statements, specifically control flow statements, that you can use to incorporate a great deal of interactivity in your application. This chapter provides an overview of these statements.
13 Details of the object model Guide, Intermediate, JavaScript, Object
JavaScript is an object-based language based on prototypes, rather than being class-based. Because of this different basis, it can be less apparent how JavaScript allows you to create hierarchies of objects and to have inheritance of properties and their values. This chapter attempts to clarify the situation.
14 Expressions and operators Beginner, Expressions, Guide, JavaScript, Operators
This chapter describes JavaScript's expressions and operators, including assignment, comparison, arithmetic, bitwise, logical, string, ternary and more.
15 Functions Beginner, Functions, Guide, JavaScript
Functions are one of the fundamental building blocks in JavaScript. A function is a JavaScript procedure—a set of statements that performs a task or calculates a value. To use a function, you must define it somewhere in the scope from which you wish to call it.
16 Grammar and types Guide, JavaScript, guide
This chapter discusses JavaScript's basic grammar, variable declarations, data types and literals.
17 Indexed collections Guide, JavaScript, Method
This chapter introduces collections of data which are ordered by an index value. This includes arrays and array-like constructs such as Array objects and TypedArray objects.
18 Introduction Guide, JavaScript, guide
This chapter introduces JavaScript and discusses some of its fundamental concepts.
19 Iterators and generators Guide, Intermediate, JavaScript, guide
Processing each of the items in a collection is a very common operation. JavaScript provides a number of ways of iterating over a collection, from simple for loops to map(), filter() and array comprehensions. Iterators and Generators bring the concept of iteration directly into the core language and provide a mechanism for customizing the behavior of for...of loops.
20 Keyed collections Collections, Guide, JavaScript, Map, set
This chapter introduces collections of data which are ordered by a key; Map and Set objects contain elements which are iterable in the order of insertion.
21 Loops and iteration Guide, JavaScript, Loop, Syntax
Loops offer a quick and easy way to do something repeatedly. This chapter of the JavaScript Guide introduces the different iteration statements available to JavaScript.
22 Meta programming Guide, JavaScript, Proxy, Reflect, guide
Starting with ECMAScript 6, JavaScript gains support for the Proxy and Reflect objects allowing you to intercept and define custom behavior for fundamental language operations (e.g. property lookup, assignment, enumeration, function invocation, etc). With the help of these two objects you are able to program at the meta level of JavaScript.
23 Numbers and dates Guide, JavaScript
This chapter introduces how to work with numbers and dates in JavaScript.
24 Regular Expressions Guide, Intermediate, JavaScript, Reference, Regular Expressions, Référence, guide
Regular expressions are patterns used to match character combinations in strings. In JavaScript, regular expressions are also objects. These patterns are used with the exec and test methods of RegExp, and with the match, replacesearch, and split methods of String. This chapter describes JavaScript regular expressions.
25 Text formatting Guide, JavaScript
This chapter introduces how to work with strings and text in JavaScript.
26 Working with objects Beginner, Comparing object, Constructor, Document, Guide, JavaScript, Object, beginner, guide
JavaScript is designed on a simple object-based paradigm. An object is a collection of properties, and a property is an association between a name and a value. A property's value can be a function, in which case the property is known as a method. In addition to objects that are predefined in the browser, you can define your own objects. This chapter describes how to use objects, properties, functions, and methods, and how to create your own objects.
27 JavaScript data types and data structures Beginner, JavaScript, Types, beginner
Programming languages all have built-in data structures, but these often differ from one language to another. This article attempts to list the built-in data structures available in JavaScript and what properties they have; these can be used to build other data structures. When possible, comparisons with other languages are drawn.
28 JavaScript language resources Advanced, JavaScript
ECMAScript is the scripting language that forms the basis of JavaScript. ECMAScript is standardized by the Ecma International standards organization in the ECMA-262 and ECMA-402 specifications. The following ECMAScript standards have been approved:
29 JavaScript reference JavaScript
This part of the JavaScript section on MDN serves as a repository of facts about the JavaScript language. Read more about this reference.
30 About this reference JavaScript
The JavaScript reference serves as a repository of facts about the JavaScript language. The entire language is described here in detail. As you write JavaScript code, you'll refer to these pages often (thus the title "JavaScript reference"). If you're learning JavaScript, or need help understanding some of its capabilities or features, check out the JavaScript guide.
31 Classes Classes, ECMAScript6, Experimental, Intermediate, JavaScript, NeedsContent, Reference
JavaScript classes are introduced in ECMAScript 6 and are syntactical sugar over JavaScript's existing prototype-based inheritance. The class syntax is not introducing a new object-oriented inheritance model to JavaScript. JS classes provide a much simpler and clearer syntax to create objects and dealing with inheritance.
32 constructor Classes, ECMAScript6, Experimental, Expérimental, JavaScript
The constructor method is a special method for creating and initializing an object created with a class.
33 extends Classes, ECMAScript6, Experimental, Expérimental, JavaScript
The extends keyword is used in a class declarations or class expressions to create a class with a child of another class.
34 static Classes, ECMAScript6, Experimental, Expérimental, JavaScript
The static keyword defines a static method for a class.
35 Deprecated and obsolete features Deprecated, JavaScript, Obsolete
This page lists features of JavaScript that are deprecated (that is, still available but planned for removal) and obsolete (that is, no longer usable).
36 The legacy Iterator protocol JavaScript, Legacy Iterator
Firefox, prior to version 26 implemented another iterator protocol that is similar to the standard ES6 Iterator protocol.
37 Expressions and operators JavaScript, Operators
This chapter documents all the JavaScript language operators, expressions and keywords.
38 Arithmetic operators JavaScript, Operator
Arithmetic operators take numerical values (either literals or variables) as their operands and return a single numerical value. The standard arithmetic operators are addition (+), subtraction (-), multiplication (*), and division (/).
39 Array comprehensions ECMAScript7, JavaScript, Operator, Reference
The array comprehension syntax is a JavaScript expression which allows you to quickly assemble a new array based on an existing one. Comprehensions exist in many programming languages and the upcoming ECMAScript 7 standard defines array comprehensions for JavaScript.
40 Assignment operators JavaScript, Operator
An assignment operator assigns a value to its left operand based on the value of its right operand.
41 Bitwise operators JavaScript, Operator, Reference
Bitwise operators treat their operands as a sequence of 32 bits (zeroes and ones), rather than as decimal, hexadecimal, or octal numbers. For example, the decimal number nine has a binary representation of 1001. Bitwise operators perform their operations on such binary representations, but they return standard JavaScript numerical values.
42 Comma operator JavaScript, Operator
The comma operator evaluates each of its operands (from left to right) and returns the value of the last operand.
43 Comparison operators JavaScript, Operator
JavaScript has both strict and type–converting comparisons. A strict comparison (e.g., ===) is only true if the operands are of the same type. The more commonly used abstract comparison (e.g. ==) converts the operands to the same Type before making the comparison. For relational abstract comparisons (e.g., <=), the operands are first converted to primitives, then to the same type, before comparison.
44 Conditional (ternary) Operator JavaScript, Operator
The conditional (ternary) operator is the only JavaScript operator that takes three operands. This operator is frequently used as a shortcut for the if statement.
45 Destructuring assignment Destructuring, JavaScript, Operator
The destructuring assignment syntax is a JavaScript expression that makes it possible to extract data from arrays or objects using a syntax that mirrors the construction of array and object literals.
46 Expression closures Functions, JavaScript, Non-standard, Reference, Réference, Référence
Expression closures are a shorthand function syntax for writing simple functions.
47 Generator comprehensions ECMAScript7, Iterator, JavaScript, Reference
The generator comprehension syntax is a JavaScript expression which allows you to quickly assemble a new generator function based on an existing iterable object. Comprehensions exist in many programming languages and the upcoming ECMAScript 7 standard defines array comprehensions for JavaScript.
48 Grouping operator JavaScript, Operator, Primary Expressions
The grouping operator ( ) controls the precedence of evaluation in expressions.
49 Legacy generator function expression JavaScript, Legacy Iterator, Non-standard, Reference, Réference, Référence
The function keyword can be used to define a legacy generator function inside an expression. To make the function a legacy generator, the function body should contain at least one yield expression.
50 Logical Operators JavaScript, Operator
Logical operators are typically used with Boolean (logical) values. When they are, they return a Boolean value. However, the && and || operators actually return the value of one of the specified operands, so if these operators are used with non-Boolean values, they may return a non-Boolean value.
51 Object initializer ECMAScript6, JSON, JavaScript, Literal, Methods, Object, Primary Expression, computed, mutation, properties
Objects can be initialized using new Object(), Object.create(), or using the literal notation (initializer notation). An object initializer is a list of zero or more pairs of property names and associated values of an object, enclosed in curly braces ({}).
52 Operator precedence JavaScript, Operator, operator details, operator precedence
Operator precedence determines the order in which operators are evaluated. Operators with higher precedence are evaluated first.
53 Property accessors JavaScript, Operator
Property accessors provide access to an object's properties by using the dot notation or the bracket notation.
54 Spread operator Experimental, JavaScript, Operator
The spread operator allows an expression to be expanded in places where multiple arguments (for function calls) or multiple elements (for array literals) are expected.
55 class expression ECMAScript6, Experimental, Expression, JavaScript, Operator, Reference
The class expression is one way define a class in ECMAScript 6. Similar to function expressions, class expressions can be named or unnamed. If named, the name of the class is local the class body only. JavaScript classes are using prototype-based inheritance.
56 delete operator JavaScript, Operator, Unary
The delete operator removes a property from an object.
57 function expression Function, JavaScript, Operator, Primary Expressions
The function keyword can be used to define a function inside an expression.
58 function* expression ECMAScript6, Experimental, Expérimental, Function, Iterator, JavaScript, Operator, Primary Expression
The function* keyword can be used to define a generator function inside an expression.
59 in operator JavaScript, Operator, Relational Operators
The in operator returns true if the specified property is in the specified object.
60 instanceof JavaScript, Object, Operator, Relational Operators, instanceof, prototype
The instanceof operator tests whether an object has in its prototype chain the prototype property of a constructor.
61 new operator JavaScript, Left-hand-side expressions, Operator
The new operator creates an instance of a user-defined object type or of one of the built-in object types that has a constructor function.
62 new.target JavaScript, NeedsContent, NeedsExample, Reference
The new.target syntax is available in all functions. In constructors, new.target refers to the constructor that was invoked by new. In normal function calls, new.target is undefined.
63 super Classes, ECMAScript6, Experimental, JavaScript, Left-hand-side expressions, Operator
The super keyword is used to call functions on an object's parent.
64 this JavaScript, Operator, Primary Expressions, Reference, Référence
A function's this keyword behaves a little differently in JavaScript compared to other languages. It also has some differences between strict mode and non-strict mode.
65 typeof JavaScript, Operator, Unary
The typeof operator returns a string indicating the type of the unevaluated operand.
66 void operator JavaScript, Operator, Unary
The void operator evaluates the given expression and then returns undefined.
67 yield ECMAScript6, Experimental, Generators, Iterator, JavaScript, Operator
The yield keyword is used to pause and resume a generator function (function* or legacy generator function).
68 yield* ECMAScript6, Experimental, Generators, Iterable, Iterator, JavaScript, Operator, Reference
The yield* expression is used to delegate to another generator or iterable object.
69 Functions Function, Functions, JavaScript
Generally speaking, a function is a "subprogram" that can be called by code external (or internal in the case of recursion) to the function. Like the program itself, a function is composed of a sequence of statements called the function body. Values can be passed to a function, and the function can return a value.
70 Arguments object Functions, JavaScript, arguments
The arguments object is an Array-like object corresponding to the arguments passed to a function.
71 arguments.callee Deprecated, Functions, JavaScript, Property, arguments, deprecated
The arguments.callee property contains the currently executing function.
72 arguments.caller Functions, JavaScript, Non-standard, Obsolete, Property, arguments
The obsolete arguments.caller property used to provide the function that invoked the currently executing function. This property has been removed and no longer works.
73 arguments.length Functions, JavaScript, Property, arguments
The arguments.length property contains the number of arguments passed to the function.
74 Arrow functions ECMAScript6, Functions, Guide, Intermediate, JavaScript, guide
An arrow function expression (also known as fat arrow function) has a shorter syntax compared to function expressions and lexically binds the this value. Arrow functions are always anonymous.
75 Default parameters ECMAScript6, Experimental, Expérimental, Functions, JavaScript
Default function parameters allow formal parameters to be initialized with default values if no value or undefined is passed.
76 Method definitions ECMAScript6, Functions, JavaScript, Object, Syntax
Starting with ECMAScript 6, a shorter syntax for method definitions on objects initializers is introduced. It is a shorthand for a function assigned to the method's name.
77 Rest parameters Functions, JavaScript, Rest, Rest parameters
The rest parameter syntax allows to represent an indefinite number of arguments as an array.
78 getter ECMAScript5, ECMAScript6, Functions, JavaScript
The get syntax binds an object property to a function that will be called when that property is looked up.
79 setter ECMAScript5, Functions, JavaScript
The set syntax binds an object property to a function to be called when there is an attempt to set that property.
80 Iteration protocols ECMAScript6, Experimental, Expérimental, Intermediate, Iterable, Iterator, JavaScript
One addition of ECMAScript 6 is not new syntax or a new built-in, but a protocol. This protocol can be implemented by any object respecting some conventions.
81 JavaScript methods index JavaScript
This article entails a listing of all JavaScript methods documented on MDN sorted alphabetically.
82 JavaScript properties index JavaScript
This article entails a listing of all JavaScript properties documented on MDN sorted alphabetically.
83 Lexical grammar JavaScript, Lexical Grammar
This section describes JavaScript's lexical grammar. The source text of ECMAScript scripts gets scanned from left to right and is converted into a sequence of input elements which are tokens, control characters, line terminators, comments or white space. ECMAScript also defines certain keywords and literals and has rules for automatic insertion of semicolons to end statements.
84 Standard built-in objects JavaScript, Reference, Référence, objects
This chapter documents all of JavaScript's standard, built-in objects, including their methods and properties.
85 Array Array, JavaScript
The JavaScript Array global object is a constructor for arrays, which are high-level, list-like objects.
86 Array.from() Array, ECMAScript6, Experimental, Expérimental, JavaScript, Method, from, polyfill
The Array.from() method creates a new Array instance from an array-like or iterable object.
87 Array.isArray() Array, ECMAScript5, JavaScript, Method, method, polyfill
The Array.isArray() method returns true if an object is an array, false if it is not.
88 Array.observe() Array, ECMAScript7, Experimental, Expérimental, JavaScript, Method
The Array.observe() method is used for asynchronously observing changes to Arrays, similar to Object.observe() for objects. It provides a stream of changes in order of occurrence. It's equivalent to Object.observe() invoked with the accept type list ["add", "update", "delete", "splice"].
89 Array.of() Array, ECMAScript6, Experimental, Expérimental, JavaScript, Method, polyfill
The Array.of() method creates a new Array instance with a variable number of arguments, regardless of number or type of the arguments.
90 Array.prototype Array, JavaScript, Property
The Array.prototype property represents the prototype for the Array constructor.
91 Array.prototype.concat() Array, JavaScript, Method, method, prototype
The concat() method returns a new array comprised of the array on which it is called joined with the array(s) and/or value(s) provided as arguments.
92 Array.prototype.copyWithin() Array, ECMAScript6, Experimental, Expérimental, JavaScript, Method, polyfill, prototype
The copyWithin() method copies the sequence of array elements within the array to the position starting at target. The copy is taken from the index positions of the second and third arguments start and end. The end argument is optional and defaults to the length of the array.
93 Array.prototype.entries() Array, ECMAScript6, Experimental, Expérimental, Iterator, JavaScript, Method, method, prototype
The entries() method returns a new Array Iterator object that contains the key/value pairs for each index in the array.
94 Array.prototype.every() Array, ECMAScript5, JavaScript, JavaScript 1.6, Method, polyfill, prototype
The every() method tests whether all elements in the array pass the test implemented by the provided function.
95 Array.prototype.fill() Array, ECMAScript6, Experimental, Expérimental, JavaScript, Method, polyfill, prototype
The fill() method fills all the elements of an array from a start index to an end index with a static value.
96 Array.prototype.filter() Array, ECMAScript5, JavaScript, Method, Reference, Référence, polyfill, prototype
The filter() method creates a new array with all elements that pass the test implemented by the provided function.
97 Array.prototype.find() Array, ECMAScript6, Experimental, Expérimental, JavaScript, Method, polyfill, prototype
The find() method returns a value in the array, if an element in the array satisfies the provided testing function. Otherwise undefined is returned.
98 Array.prototype.findIndex() Array, ECMAScript6, Experimental, Expérimental, JavaScript, Method, method, polyfill, prototype
The findIndex() method returns an index in the array, if an element in the array satisfies the provided testing function. Otherwise -1 is returned.
99 Array.prototype.forEach() Array, ECMAScript5, JavaScript, JavaScript 1.6, Method, Reference, Référence, polyfill, prototype
The forEach() method executes a provided function once per array element.
100 Array.prototype.includes() Array, ECMAScript7, Experimental, Expérimental, JavaScript, Method, polyfill, prototype
The includes() method determines whether an array includes a certain element, returning true or false as appropriate.
101 Array.prototype.indexOf() Array, JavaScript, Method, Reference, Référence, polyfill, prototype
The indexOf() method returns the first index at which a given element can be found in the array, or -1 if it is not present.
102 Array.prototype.join() Array, JavaScript, Method, Reference, Référence, prototype
The join() method joins all elements of an array into a string.
103 Array.prototype.keys() Array, ECMAScript6, Experimental, Expérimental, Iterator, JavaScript, Method, prototype
The keys() method returns a new Array Iterator that contains the keys for each index in the array.
104 Array.prototype.lastIndexOf() Array, ECMAScript5, JavaScript, Method, polyfill, prototype
The lastIndexOf() method returns the last index at which a given element can be found in the array, or -1 if it is not present. The array is searched backwards, starting at fromIndex.
105 Array.prototype.length Array, JavaScript, Property
The length property represents an unsigned, 32-bit integer that specifies the number of elements in an array.
106 Array.prototype.map() Array, ECMAScript5, JavaScript, JavaScript 1.6, Method, polyfill, prototype
The map() method creates a new array with the results of calling a provided function on every element in this array.
107 Array.prototype.pop() Array, JavaScript, Method, prototype
The pop() method removes the last element from an array and returns that element.
108 Array.prototype.push() Array, JavaScript, Method, Reference, Référence, prototype
The push() method adds one or more elements to the end of an array and returns the new length of the array.
109 Array.prototype.reduce() Array, ECMAScript5, JavaScript, JavaScript 1.8, Method, polyfill, prototype
The reduce() method applies a function against an accumulator and each value of the array (from left-to-right) to reduce it to a single value.
110 Array.prototype.reduceRight() Array, ECMAScript5, JavaScript, JavaScript 1.8, Method, polyfill, prototype
The reduceRight() method applies a function against an accumulator and each value of the array (from right-to-left) has to reduce it to a single value.
111 Array.prototype.reverse() Array, JavaScript, Method, method, prototype
The reverse() method reverses an array in place. The first array element becomes the last and the last becomes the first.
112 Array.prototype.shift() Array, JavaScript, Method, prototype
The shift() method removes the first element from an array and returns that element. This method changes the length of the array.
113 Array.prototype.slice() Array, JavaScript, Method, prototype
The slice() method returns a shallow copy of a portion of an array into a new array object.
114 Array.prototype.some() Array, ECMAScript5, JavaScript, JavaScript 1.6, Method, Reference, prototype
The some() method tests whether some element in the array passes the test implemented by the provided function.
115 Array.prototype.sort() Array, JavaScript, Method, prototype
The sort() method sorts the elements of an array in place and returns the array. The sort is not necessarily stable. The default sort order is according to string Unicode code points.
116 Array.prototype.splice() Array, JavaScript, Method, Reference, Référence, prototype
The splice() method changes the content of an array by removing existing elements and/or adding new elements.
117 Array.prototype.toLocaleString() Array, Internationalization, JavaScript, Method, prototype
The toLocaleString() method returns a string representing the elements of the array. The elements are converted to Strings using their toLocaleString methods and these Strings are separated by a locale-specific String (such as a comma “,”).
118 Array.prototype.toSource() Array, JavaScript, Method, Non-standard, prototype
The toSource() method returns a string representing the source code of the array.
119 Array.prototype.toString() Array, JavaScript, Method, prototype
The toString() method returns a string representing the specified array and its elements.
120 Array.prototype.unshift() Array, JavaScript, Method, prototype
The unshift() method adds one or more elements to the beginning of an array and returns the new length of the array.
121 Array.prototype.values() Array, ECMAScript6, Experimental, Expérimental, Iterator, JavaScript, Method, prototype
The values() method returns a new Array Iterator object that contains the values for each index in the array.
122 Array.prototype[@@iterator]() Array, ECMAScript6, Experimental, Expérimental, Iterator, JavaScript, Method, Reference, Référence, prototype
The initial value of the @@iterator property is the same function object as the initial value of the values() property.
123 Array.unobserve() Array, Experimental, JavaScript, Method
The Array.unobserve() method is used to remove observers set by Array.observe().
124 ArrayBuffer ArrayBuffer, Constructor, JavaScript, TypedArrays, arrayBuffer
The ArrayBuffer object is used to represent a generic, fixed-length raw binary data buffer. You can not directly manipulate the contents of an ArrayBuffer; instead, you create one of the typed array objects or a DataView object which represents the buffer in a specific format, and use that to read and write the contents of the buffer.
125 ArrayBuffer.isView() ArrayBuffer, JavaScript, Method, TypedArrays, arrayBuffer
The ArrayBuffer.isView() method returns true if arg is a view one of the ArrayBuffer views, such as typed array objects or a DataView; false otherwise.
126 ArrayBuffer.prototype ArrayBuffer, JavaScript, Property, arrayBuffer
The ArrayBuffer.prototype property represents the prototype for the ArrayBuffer object.
127 ArrayBuffer.prototype.byteLength ArrayBuffer, JavaScript, Property, arrayBuffer, prototype
The byteLength accessor property represents the length of an ArrayBuffer in bytes.
128 ArrayBuffer.prototype.slice() ArrayBuffer, JavaScript, Method, arrayBuffer, prototype
The slice() method returns a new ArrayBuffer whose contents are a copy of this ArrayBuffer's bytes from begin, inclusive, up to end, exclusive.
129 ArrayBuffer.transfer() ArrayBuffer, ECMAScript7, Experimental, Expérimental, JavaScript, Method, Reference, Référence, TypedArrays, arrayBuffer
The static ArrayBuffer.transfer() method returns a new ArrayBuffer whose contents are taken from the oldBuffer's data and then is either truncated or zero-extended by newByteLength. If newByteLength is undefined, the byteLength of the oldBuffer is used. This operation leaves oldBuffer in a detached state.
130 Boolean Boolean, Constructor, JavaScript
The Boolean object is an object wrapper for a boolean value.
131 Boolean.prototype Boolean, JavaScript, Property, prototype
The Boolean.prototype property represents the prototype for the Boolean constructor.
132 Boolean.prototype.toSource() Boolean, JavaScript, Method, Non-standard, prototype
The toSource() method returns a string representing the source code of the object.
133 Boolean.prototype.toString() Boolean, JavaScript, Method, prototype
The toString() method returns a string representing the specified Boolean object.
134 Boolean.prototype.valueOf() Boolean, JavaScript, Method, prototype
The valueOf() method returns the primitive value of a Boolean object.
135 DataView Constructor, DataView, JavaScript, TypedArrays
The DataView view provides a low-level interface for reading data from and writing it to an ArrayBuffer.
136 DataView.prototype DataView, JavaScript, Property
The DataView.prototype property represents the prototype for the DataView object.
137 DataView.prototype.buffer DataView, JavaScript, Property, TypedArrays, prototype
The buffer accessor property represents the ArrayBuffer referenced by the DataView at construction time.
138 DataView.prototype.byteLength DataView, JavaScript, Property, TypedArrays, prototype
The byteLength accessor property represents the length (in bytes) of this view from the start of its ArrayBuffer.
139 DataView.prototype.byteOffset DataView, JavaScript, Property, TypedArrays, prototype
The byteOffset accessor property represents the offset (in bytes) of this view from the start of its ArrayBuffer.
140 DataView.prototype.getFloat32() DataView, JavaScript, Method, TypedArrays, prototype
The getFloat32() method gets a signed 32-bit float (float) at the specified byte offset from the start of the DataView.
141 DataView.prototype.getFloat64() DataView, JavaScript, Method, TypedArrays, prototype
The getFloat64() method gets a signed 64-bit float (double) at the specified byte offset from the start of the DataView.
142 DataView.prototype.getInt16() DataView, JavaScript, Method, TypedArrays, prototype
The getInt16() method gets a signed 16-bit integer (short) at the specified byte offset from the start of the DataView.
143 DataView.prototype.getInt32() DataView, JavaScript, Method, TypedArrays, prototype
The getInt32() method gets a signed 32-bit integer (long) at the specified byte offset from the start of the DataView.
144 DataView.prototype.getInt8() DataView, JavaScript, Method, TypedArrays, prototype
The getInt8() method gets a signed 8-bit integer (byte) at the specified byte offset from the start of the DataView.
145 DataView.prototype.getUint16() DataView, JavaScript, Method, TypedArrays, prototype
The getUint16() method gets an unsigned 16-bit integer (unsigned short) at the specified byte offset from the start of the DataView.
146 DataView.prototype.getUint32() DataView, JavaScript, Method, TypedArrays, prototype
The getUint32() method gets an unsigned 32-bit integer (unsigned long) at the specified byte offset from the start of the DataView.
147 DataView.prototype.getUint8() DataView, JavaScript, Method, TypedArrays, prototype
The getUint8() method gets an unsigned 8-bit integer (unsigned byte) at the specified byte offset from the start of the DataView.
148 DataView.prototype.setFloat32() DataView, JavaScript, Method, TypedArrays, prototype
The setFloat32() method stores a signed 32-bit float (float) value at the specified byte offset from the start of the DataView.
149 DataView.prototype.setFloat64() DataView, JavaScript, Method, TypedArrays, prototype
The setFloat64() method stores a signed 64-bit float (double) value at the specified byte offset from the start of the DataView.
150 DataView.prototype.setInt16() DataView, JavaScript, Method, TypedArrays, prototype
The setInt16() method stores a signed 16-bit integer (short) value at the specified byte offset from the start of the DataView.
151 DataView.prototype.setInt32() DataView, JavaScript, Method, TypedArrays, prototype
The setInt32() method stores a signed 32-bit integer (long) value at the specified byte offset from the start of the DataView.
152 DataView.prototype.setInt8() DataView, JavaScript, Method, TypedArrays, prototype
The setInt8() method stores a signed 8-bit integer (byte) value at the specified byte offset from the start of the DataView.
153 DataView.prototype.setUint16() DataView, JavaScript, Method, TypedArrays, prototype
The setUint16() method stores an unsigned 16-bit integer (unsigned short) value at the specified byte offset from the start of the DataView.
154 DataView.prototype.setUint32() DataView, JavaScript, Method, TypedArrays, prototype
The setUint32() method stores an unsigned 32-bit integer (unsigned long) value at the specified byte offset from the start of the DataView.
155 DataView.prototype.setUint8() DataView, JavaScript, Method, TypedArrays, prototype
The setUint8() method stores an unsigned 8-bit integer (byte) value at the specified byte offset from the start of the DataView.
156 Date Date, JavaScript
Creates a JavaScript Date instance that represents a single moment in time. Date objects are based on a time value that is the number of milliseconds since 1 January, 1970 UTC.
157 Date.UTC() Date, JavaScript, Method, Reference
The Date.UTC() method accepts the same parameters as the longest form of the constructor, and returns the number of milliseconds in a Date object since January 1, 1970, 00:00:00, universal time.
158 Date.now() Date, JavaScript, Method, Reference, Référence, polyfill
The Date.now() method returns the number of milliseconds elapsed since 1 January 1970 00:00:00 UTC.
159 Date.parse() Date, JavaScript, Method, Reference
The Date.parse() method parses a string representation of a date, and returns the number of milliseconds since January 1, 1970, 00:00:00 UTC.
160 Date.prototype Date, JavaScript, Property, Reference, prototype
The Date.prototype property represents the prototype for the Date constructor.
161 Date.prototype.getDate() Date, JavaScript, Method, Reference, prototype
The getDate() method returns the day of the month for the specified date according to local time.
162 Date.prototype.getDay() Date, JavaScript, Method, Reference, prototype
The getDay() method returns the day of the week for the specified date according to local time, where 0 represents Sunday.
163 Date.prototype.getFullYear() Date, JavaScript, Method, Reference, Référence, method, prototype
The getFullYear() method returns the year of the specified date according to local time.
164 Date.prototype.getHours() Date, JavaScript, Method, Reference, Référence, method, prototype
The getHours() method returns the hour for the specified date, according to local time.
165 Date.prototype.getMilliseconds() Date, JavaScript, Method, Reference, Référence, method, prototype
The getMilliseconds() method returns the milliseconds in the specified date according to local time.
166 Date.prototype.getMinutes() Date, JavaScript, Method, Reference, Référence, method, prototype
The getMinutes() method returns the minutes in the specified date according to local time.
167 Date.prototype.getMonth() Date, JavaScript, Method, Reference, Référence, prototype
The getMonth() method returns the month in the specified date according to local time, as a zero-based value (where zero indicates the first month of the year).
168 Date.prototype.getSeconds() Date, JavaScript, Method, Reference, Référence, prototype
The getSeconds() method returns the seconds in the specified date according to local time.
169 Date.prototype.getTime() Date, JavaScript, Method, Reference, Référence, prototype
The getTime() method returns the numeric value corresponding to the time for the specified date according to universal time.
170 Date.prototype.getTimezoneOffset() Date, JavaScript, Method, Reference, Référence, prototype
The getTimezoneOffset() method returns the time-zone offset from UTC, in minutes, for the current locale.
171 Date.prototype.getUTCDate() Date, JavaScript, Method, Reference, Référence, prototype
The getUTCDate() method returns the day (date) of the month in the specified date according to universal time.
172 Date.prototype.getUTCDay() Date, JavaScript, Method, Reference, Référence, prototype
The getUTCDay() method returns the day of the week in the specified date according to universal time, where 0 represents Sunday.
173 Date.prototype.getUTCFullYear() Date, JavaScript, Method, Reference, Référence, prototype
The getUTCFullYear() method returns the year in the specified date according to universal time.
174 Date.prototype.getUTCHours() Date, JavaScript, Method, Reference, Référence, prototype
The getUTCHours() method returns the hours in the specified date according to universal time.
175 Date.prototype.getUTCMilliseconds() Date, JavaScript, Method, Reference, Référence, prototype
The getUTCMilliseconds() method returns the milliseconds in the specified date according to universal time.
176 Date.prototype.getUTCMinutes() Date, JavaScript, Method, Reference, Référence, prototype
The getUTCMinutes() method returns the minutes in the specified date according to universal time.
177 Date.prototype.getUTCMonth() Date, JavaScript, Method, Reference, Référence, prototype
The getUTCMonth() returns the month of the specified date according to universal time, as a zero-based value (where zero indicates the first month of the year).
178 Date.prototype.getUTCSeconds() Date, JavaScript, Method, Reference, Référence, prototype
The getUTCSeconds() method returns the seconds in the specified date according to universal time.
179 Date.prototype.getYear() Date, Deprecated, JavaScript, Method, Reference, deprecated, prototype
The getYear() method returns the year in the specified date according to local time. Because getYear() does not return full years ("year 2000 problem"), it is no longer used and has been replaced by the getFullYear() method.
180 Date.prototype.setDate() Date, JavaScript, Method, Reference, prototype
The setDate() method sets the day of the Date object relative to the beginning of the currently set month.
181 Date.prototype.setFullYear() Date, JavaScript, Method, Reference, prototype
The setFullYear() method sets the full year for a specified date according to local time. Returns new timestamp.
182 Date.prototype.setHours() Date, JavaScript, Method, Reference, prototype
The setHours() method sets the hours for a specified date according to local time, and returns the number of milliseconds since 1 January 1970 00:00:00 UTC until the time represented by the updated Date instance.
183 Date.prototype.setMilliseconds() Date, JavaScript, Method, Reference, prototype
The setMilliseconds() method sets the milliseconds for a specified date according to local time.
184 Date.prototype.setMinutes() Date, JavaScript, Method, Reference, prototype
The setMinutes() method sets the minutes for a specified date according to local time.
185 Date.prototype.setMonth() Date, JavaScript, Method, Reference, prototype
The setMonth() method sets the month for a specified date according to the currently set year.
186 Date.prototype.setSeconds() Date, JavaScript, Method, Reference, prototype
The setSeconds() method sets the seconds for a specified date according to local time.
187 Date.prototype.setTime() Date, JavaScript, Method, Reference, prototype
The setTime() method sets the Date object to the time represented by a number of milliseconds since January 1, 1970, 00:00:00 UTC.
188 Date.prototype.setUTCDate() Date, JavaScript, Method, Reference, prototype
The setUTCDate() method sets the day of the month for a specified date according to universal time.
189 Date.prototype.setUTCFullYear() Date, JavaScript, Method, Reference, prototype
The setUTCFullYear() method sets the full year for a specified date according to universal time.
190 Date.prototype.setUTCHours() Date, JavaScript, Method, Reference, prototype
The setUTCHours() method sets the hour for a specified date according to universal time, and returns the number of milliseconds since 1 January 1970 00:00:00 UTC until the time represented by the updated Date instance.
191 Date.prototype.setUTCMilliseconds() Date, JavaScript, Method, Reference, prototype
The setUTCMilliseconds() method sets the milliseconds for a specified date according to universal time.
192 Date.prototype.setUTCMinutes() Date, JavaScript, Method, Reference, prototype
The setUTCMinutes() method sets the minutes for a specified date according to universal time.
193 Date.prototype.setUTCMonth() Date, JavaScript, Method, Reference, prototype
The setUTCMonth() method sets the month for a specified date according to universal time.
194 Date.prototype.setUTCSeconds() Date, JavaScript, Method, Reference, prototype
The setUTCSeconds() method sets the seconds for a specified date according to universal time.
195 Date.prototype.setYear() Date, Deprecated, JavaScript, Method, Reference, deprecated, prototype
The setYear() method sets the year for a specified date according to local time. Because setYear() does not set full years ("year 2000 problem"), it is no longer used and has been replaced by the setFullYear() method.
196 Date.prototype.toDateString() Date, JavaScript, Method, Reference, prototype
The toDateString() method returns the date portion of a Date object in human readable form in American English.
197 Date.prototype.toGMTString() Date, Deprecated, JavaScript, Method, Reference, deprecated, prototype
The toGMTString() method converts a date to a string, using Internet Greenwich Mean Time (GMT) conventions. The exact format of the value returned by toGMTString() varies according to the platform and browser, in general it should represent a human readable date string.
198 Date.prototype.toISOString() Date, JavaScript, Method, Reference, polyfill, prototype
The toISOString() method returns a string in simplified extended ISO format (ISO 8601), which is always 24 characters long: YYYY-MM-DDTHH:mm:ss.sssZ. The timezone is always zero UTC offset, as denoted by the suffix "Z".
199 Date.prototype.toJSON() Date, JavaScript, Method, Reference, prototype
The toJSON() method returns a string representation of the Date object.
200 Date.prototype.toLocaleDateString() Date, Internationalization, JavaScript, Method, Reference, prototype
The toLocaleDateString() method returns a string with a language sensitive representation of the date portion of this date. The new locales and options arguments let applications specify the language whose formatting conventions should be used and allow to customize the behavior of the function. In older implementations, which ignore the locales and options arguments, the locale used and the form of the string returned are entirely implementation dependent.
201 Date.prototype.toLocaleFormat() Date, JavaScript, Method, Non-standard, Reference, prototype
The non-standard toLocaleFormat() method converts a date to a string using the specified formatting. Intl.DateTimeFormat is an alternative to format dates in a standards-compliant way. See also the newer version of Date.prototype.toLocaleDateString().
202 Date.prototype.toLocaleString() Date, Internationalization, JavaScript, Method, Reference, prototype
The toLocaleString() method returns a string with a language sensitive representation of this date. The new locales and options arguments let applications specify the language whose formatting conventions should be used and customize the behavior of the function. In older implementations, which ignore the locales and options arguments, the locale used and the form of the string returned are entirely implementation dependent.
203 Date.prototype.toLocaleTimeString() Date, Internationalization, JavaScript, Method, Reference, prototype
The toLocaleTimeString() method returns a string with a language sensitive representation of the time portion of this date. The new locales and options arguments let applications specify the language whose formatting conventions should be used and customize the behavior of the function. In older implementations, which ignore the locales and options arguments, the locale used and the form of the string returned are entirely implementation dependent.
204 Date.prototype.toSource() Date, JavaScript, Method, Non-standard, Reference, prototype
The toSource() method returns a string representing the source code of the object.
205 Date.prototype.toString() Date, JavaScript, Method, Reference, prototype
The toString() method returns a string representing the specified Date object.
206 Date.prototype.toTimeString() Date, JavaScript, Method, Reference, prototype
The toTimeString() method returns the time portion of a Date object in human readable form in American English.
207 Date.prototype.toUTCString() Date, JavaScript, Method, Reference, prototype
The toUTCString() method converts a date to a string, using the UTC time zone.
208 Date.prototype.valueOf() Date, JavaScript, Method, Reference, prototype
The valueOf() method returns the primitive value of a Date object.
209 Error Error, JavaScript, Reference
The Error constructor creates an error object. Instances of Error objects are thrown when runtime errors occur. The Error object can also be used as a base objects for user-defined exceptions. See below for standard built-in error types.
210 Error.prototype Error, JavaScript, Property
The Error.prototype property represents the prototype for the Error constructor.
211 Error.prototype.columnNumber Error, JavaScript, Non-standard, Property, prototype
The columnNumber property contains the column number in the line of the file that raised this error.
212 Error.prototype.fileName Error, JavaScript, Non-standard, Property, prototype
The fileName property contains the path to the file that raised this error.
213 Error.prototype.lineNumber Error, JavaScript, Non-standard, Property, Reference, prototype
The lineNumber property contains the line number in the file that raised this error.
214 Error.prototype.message Error, JavaScript, Property, prototype
The message property is a human-readable description of the error.
215 Error.prototype.name Error, JavaScript, Property, prototype
The name property represents a name for the type of error. The initial value is "Error".
216 Error.prototype.stack Error, JavaScript, Non-standard, Property, Reference, prototype
The non-standard stack property of Error objects offer a trace of which functions were called, in what order, from which line and file, and with what arguments. The stack string proceeds from the most recent calls to earlier ones, leading back to the original global scope call.
217 Error.prototype.toSource() Error, JavaScript, Method, Non-standard, prototype
The toSource() method returns code that could eval to the same error.
218 Error.prototype.toString() Error, JavaScript, Method, prototype
The toString() method returns a string representing the specified Error object.
219 EvalError Error, EvalError, JavaScript, Reference
The EvalError object indicates an error regarding the global eval() function.
220 EvalError.prototype Error, EvalError, JavaScript, Property
The EvalError.prototype property represents the prototype of the EvalError constructor.
221 Float32Array Constructor, JavaScript, TypedArray, TypedArrays
The Float32Array typed array represents an array of 32-bit floating point numbers (corresponding to the C float data type) in the platform byte order. If control over byte order is needed, use DataView instead. The contents are initialized to 0. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).
222 Float64Array Constructor, JavaScript, TypedArray, TypedArrays
The Float64Array typed array represents an array of 64-bit floating point numbers (corresponding to the C double data type) in the platform byte order. If control over byte order is needed, use DataView instead. The contents are initialized to 0. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).
223 Function Constructor, Function, JavaScript
The Function constructor creates a new Function object. In JavaScript every function is actually a Function object.
224 Function.arguments Deprecated, Function, JavaScript, Property, arguments, deprecated
The function.arguments property refers to an an array-like object corresponding to the arguments passed to a function. Use the simple variable arguments instead.
225 Function.arity Function, JavaScript, Non-standard, Obsolete, Property, Unimplemented
The arity property used to return the number of arguments expected by the function, however, it no longer exists and has been replaced by the Function.prototype.length property.
226 Function.caller Function, JavaScript, Non-standard, Property
The function.caller property returns the function that invoked the specified function.
227 Function.displayName Function, JavaScript, Non-standard, Property
The function.displayName property returns the display name of the function.
228 Function.length Function, JavaScript, Property
The length property specifies the number of arguments expected by the function.
229 Function.name ECMAScript6, Experimental, Expérimental, Function, JavaScript, Property
The function.name property returns the name of the function.
230 Function.prototype Function, JavaScript, Property, prototype
The Function.prototype property represents the Function prototype object.
231 Function.prototype.apply() Function, JavaScript, Method
The apply() method calls a function with a given this value and arguments provided as an array (or an array-like object).
232 Function.prototype.bind() ECMAScript5, Function, JavaScript, Method, polyfill
The bind() method creates a new function that, when called, has its this keyword set to the provided value, with a given sequence of arguments preceding any provided when the new function is called.
233 Function.prototype.call() Function, JavaScript, Method
The call() method calls a function with a given this value and arguments provided individually.
234 Function.prototype.isGenerator() Function, JavaScript, Method, Non-standard
The isGenerator() method determines whether or not a function is a generator.
235 Function.prototype.toSource() Function, JavaScript, Method, Non-standard
The toSource() method returns a string representing the source code of the object.
236 Function.prototype.toString() Function, JavaScript, Method, prototype
The toString() method returns a string representing the source code of the function.
237 Generator ECMAScript6, Experimental, Expérimental, Generator, JavaScript, Legacy Generator, Legacy Iterator, Reference, Référence
The Generator object is returned by a generator function and it conforms to both the iterator and the Iterable protocol.
238 Generator.prototype.next() ECMAScript6, Experimental, Expérimental, Generator, JavaScript, Method, Reference, Réference, Référence, prototype
The next() method returns an object with two properties done and value. You can also provide a parameter to the next method to send a value to the generator.
239 Generator.prototype.return() ECMAScript6, Experimental, Expérimental, Generator, JavaScript, Method, Reference, Référence, prototype
The return() method returns the given value and finishes the generator.
240 Generator.prototype.throw() ECMAScript6, Experimental, Expérimental, Generator, JavaScript, Method, Reference, Référence, prototype
The throw() method throws an error to a generator.
241 GeneratorFunction Constructor, ECMAScript6, Experimental, Expérimental, GeneratorFunction, Iterator, JavaScript, Reference, Référence
The GeneratorFunction constructor creates a new generator function object. In JavaScript every generator function is actually a GeneratorFunction object.
242 GeneratorFunction.prototype ECMAScript6, Experimental, Expérimental, GeneratorFunction, Iterator, JavaScript, Property, Reference, Référence, prototype
The GeneratorFunction.prototype property represents the GeneratorFunction prototype object.
243 Infinity JavaScript
The global Infinity property is a numeric value representing infinity.
244 Int16Array Constructor, JavaScript, TypedArray, TypedArrays
The Int16Array typed array represents an array of twos-complement 16-bit signed integers in the platform byte order. If control over byte order is needed, use DataView instead. The contents are initialized to 0. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).
245 Int32Array Constructor, JavaScript, TypedArray, TypedArrays
The Int32Array typed array represents an array of twos-complement 32-bit signed integers in the platform byte order. If control over byte order is needed, use DataView instead. The contents are initialized to 0. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).
246 Int8Array Constructor, Int8Array, JavaScript, TypedArray, TypedArrays
The Int8Array typed array represents an array of twos-complement 8-bit signed integers. The contents are initialized to 0. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).
247 InternalError Error, InternalError, JavaScript, Non-standard
The InternalError object indicates an error that occurred internally in the JavaScript engine. For example: "InternalError: too much recursion".
248 InternalError.prototype Error, InternalError, JavaScript, Non-standard, Property
The InternalError.prototype property represents the prototype of the InternalError constructor.
249 Intl Internationalization, JavaScript
The Intl object is the namespace for the ECMAScript Internationalization API, which provides language sensitive string comparison, number formatting, and date and time formatting. The constructors for Collator, NumberFormat, and DateTimeFormat objects are properties of the Intl object. This page documents these properties as well as functionality common to the internationalization constructors and other language sensitive functions.
250 Intl.Collator Collator, Internationalization, JavaScript
The Intl.Collator object is a constructor for collators, objects that enable language sensitive string comparison.
251 Intl.Collator.prototype Collator, Internationalization, JavaScript, Property, prototype
The Intl.Collator.prototype property represents the prototype object for the Intl.Collator constructor.
252 Intl.Collator.prototype.compare Collator, Internationalization, JavaScript, Property, prototype
The Intl.Collator.prototype.compare property returns a getter function that compares two strings according to the sort order of this Collator object.
253 Intl.Collator.prototype.resolvedOptions() Collator, Internationalization, JavaScript, Method, method, prototype
The Intl.Collator.prototype.resolvedOptions() method returns a new object with properties reflecting the locale and collation options computed during initialization of this Collator object.
254 Intl.Collator.supportedLocalesOf() Collator, Internationalization, JavaScript, Method, method
The Intl.Collator.supportedLocalesOf() method returns an array containing those of the provided locales that are supported in collation without having to fall back to the runtime's default locale.
255 Intl.DateTimeFormat DateTimeFormat, Internationalization, JavaScript
The Intl.DateTimeFormat object is a constructor for objects that enable language sensitive date and time formatting.
256 Intl.DateTimeFormat.prototype DateTimeFormat, Internationalization, JavaScript, Property, prototype
The Intl.DateTimeFormat.prototype property represents the prototype object for the Intl.DateTimeFormat constructor.
257 Intl.DateTimeFormat.prototype.format DateTimeFormat, Internationalization, JavaScript, Property, prototype
The Intl.DateTimeFormat.prototype.format property returns a getter function that formats a date according to the locale and formatting options of this Intl.DateTimeFormat object.
258 Intl.DateTimeFormat.prototype.resolvedOptions() DateTimeFormat, Internationalization, JavaScript, Method, prototype
The Intl.DateTimeFormat.prototype.resolvedOptions() method returns a new object with properties reflecting the locale and date and time formatting options computed during initialization of this DateTimeFormat object.
259 Intl.DateTimeFormat.supportedLocalesOf() DateTimeFormat, Internationalization, JavaScript, Method, prototype
The Intl.DateTimeFormat.supportedLocalesOf() method returns an array containing those of the provided locales that are supported in date and time formatting without having to fall back to the runtime's default locale.
260 Intl.NumberFormat Internationalization, JavaScript, NumberFormat
The Intl.NumberFormat object is a constructor for objects that enable language sensitive number formatting.
261 Intl.NumberFormat.prototype Internationalization, JavaScript, NumberFormat, Property, prototype
The Intl.NumberFormat.prototype property represents the prototype object for the Intl.NumberFormat constructor.
262 Intl.NumberFormat.prototype.format Internationalization, JavaScript, NumberFormat, Property, prototype
The Intl.NumberFormat.prototype.format property returns a getter function that formats a number according to the locale and formatting options of this NumberFormat object.
263 Intl.NumberFormat.prototype.resolvedOptions() Internationalization, JavaScript, Method, NumberFormat, prototype
The Intl.NumberFormat.prototype.resolvedOptions() method returns a new object with properties reflecting the locale and number formatting options computed during initialization of this NumberFormat object.
264 Intl.NumberFormat.supportedLocalesOf() Internationalization, JavaScript, Method, NumberFormat
The Intl.NumberFormat.supportedLocalesOf() method returns an array containing those of the provided locales that are supported in number formatting without having to fall back to the runtime's default locale.
265 Iterator JavaScript, Legacy Iterator, Non-standard, Reference
The Iterator function returns an object which implements legacy iterator protocol and iterates over enumerable properties of an object.
266 JSON JSON, JavaScript, Object, Reference, Référence, polyfill
The JSON object contains methods for parsing JavaScript Object Notation (JSON) and converting values to JSON. It can't be called or constructed, and aside from its two method properties it has no interesting functionality of its own.
267 JSON.parse() ECMAScript5, JSON, JavaScript, Method, Reference
The JSON.parse() method parses a string as JSON, optionally transforming the value produced by parsing.
268 JSON.stringify() JSON, JavaScript, Method, Reference, stringify
The JSON.stringify() method converts a JavaScript value to a JSON string, optionally replacing values if a replacer function is specified, or optionally including only the specified properties if a replacer array is specified.
269 Map ECMAScript6, Experimental, JavaScript, Map
The Map object is a simple key/value map. Any value (both objects and primitive values) may be used as either a key or a value.
270 Map.prototype ECMAScript6, Experimental, JavaScript, Map, Property
The Map.prototype property represents the prototype for the Map constructor.
271 Map.prototype.clear() ECMAScript6, Experimental, JavaScript, Map, Method, prototype
The clear() method removes all elements from a Map object.
272 Map.prototype.delete() ECMAScript6, Experimental, JavaScript, Map, Method, prototype
The delete() method removes the specified element from a Map object.
273 Map.prototype.entries() ECMAScript6, Experimental, Iterator, JavaScript, Map, Method, prototype
The entries() method returns a new Iterator object that contains the [key, value] pairs for each element in the Map object in insertion order.
274 Map.prototype.forEach() ECMAScript6, Experimental, JavaScript, Map, Method, prototype
The forEach() method executes a provided function once per each key/value pair in the Map object, in insertion order.
275 Map.prototype.get() ECMAScript6, Experimental, JavaScript, Map, Method, prototype
The get() method returns a specified element from a Map object.
276 Map.prototype.has() ECMAScript6, Experimental, JavaScript, Map, Method, prototype
The has() method returns a boolean indicating whether an element with the specified key exists or not.
277 Map.prototype.keys() ECMAScript6, Experimental, Iterator, JavaScript, Map, Method, prototype
The keys() method returns a new Iterator object that contains the keys for each element in the Map object in insertion order.
278 Map.prototype.set() ECMAScript6, Experimental, JavaScript, Map, Method, prototype
The set() method adds a new element with a specified key and value to a Map object.
279 Map.prototype.size ECMAScript6, Experimental, Expérimental, JavaScript, Map, Property
The size accessor property returns the number of elements in a Map object.
280 Map.prototype.values() ECMAScript6, Experimental, Iterator, JavaScript, Map, Method, prototype
The values() method returns a new Iterator object that contains the values for each element in the Map object in insertion order.
281 Map.prototype[@@iterator]() ECMAScript6, Iterator, JavaScript, Map, Method, Reference, prototype
The initial value of the @@iterator property is the same function object as the initial value of the entries property.
282 Map.prototype[@@toStringTag]() ECMAScript6, JavaScript, Map, Method, NeedsExample, Reference, prototype, toStringTag
The Map[@@toStringTag] property has an initial value of "Map".
283 get Map[@@species] ECMAScript6, Experimental, Expérimental, JavaScript, Map, Property
The Map[@@species] accessor property returns the Map constructor.
284 Math JavaScript, Math, Reference
Math is a built-in object that has properties and methods for mathematical constants and functions. Not a function object.
285 Math.E JavaScript, Math, Property, Reference
The Math.E property represents the base of natural logarithms, e, approximately 2.718.
286 Math.LN10 JavaScript, Math, Property, Reference
The Math.LN10 property represents the natural logarithm of 10, approximately 2.302:
287 Math.LN2 JavaScript, Math, Property, Reference
The Math.LN2 property represents the natural logarithm of 2, approximately 0.693:
288 Math.LOG10E JavaScript, Math, Property, Reference
The Math.LOG10E property represents the base 10 logarithm of e, approximately 0.434:
289 Math.LOG2E JavaScript, Math, Property, Reference
The Math.LOG2E property represents the base 2 logarithm of e, approximately 1.442:
290 Math.PI JavaScript, Math, Property, Reference
The Math.PI property represents the ratio of the circumference of a circle to its diameter, approximately 3.14159:
291 Math.SQRT1_2 JavaScript, Math, Property, Reference
The Math.SQRT1_2 property represents the square root of 1/2 which is approximately 0.707:
292 Math.SQRT2 JavaScript, Math, Property, Reference
The Math.SQRT2 property represents the square root of 2, approximately 1.414:
293 Math.abs() JavaScript, Math, Method, Reference
The Math.abs() function returns the absolute value of a number, that is
294 Math.acos() JavaScript, Math, Method, Reference
The Math.acos() function returns the arccosine (in radians) of a number, that is
295 Math.acosh() Experimental, JavaScript, Math, Method, Reference
The Math.acosh() function returns the hyperbolic arc-cosine of a number, that is
296 Math.asin() JavaScript, Math, Method, Reference
The Math.asin() function returns the arcsine (in radians) of a number, that is
297 Math.asinh() Experimental, JavaScript, Math, Method, Reference
The Math.asinh() function returns the hyperbolic arcsine of a number, that is
298 Math.atan() JavaScript, Math, Method, Reference
The Math.atan() function returns the arctangent (in radians) of a number, that is
299 Math.atan2() JavaScript, Math, Method, Reference
The Math.atan2() function returns the arctangent of the quotient of its arguments.
300 Math.atanh() Experimental, JavaScript, Math, Method, Reference
The Math.atanh() function returns the hyperbolic arctangent of a number, that is
301 Math.cbrt() Experimental, JavaScript, Math, Method, Reference
The Math.cbrt() function returns the cube root of a number, that is
302 Math.ceil() JavaScript, Math, Method, Reference
The Math.ceil() function returns the smallest integer greater than or equal to a given number.
303 Math.clz32() ECMAScript6, Experimental, JavaScript, Math, Method, Reference
The Math.clz32() function returns the number of leading zero bits in the 32-bit binary representation of a number.
304 Math.cos() JavaScript, Math, Method, Reference
The Math.cos() function returns the cosine of a number.
305 Math.cosh() Experimental, Expérimental, JavaScript, Math, Method, Reference, Référence
The Math.cosh() function returns the hyperbolic cosine of a number, that can be expressed using the constant e:
306 Math.exp() JavaScript, Math, Method, Reference
The Math.exp() function returns ex, where x is the argument, and e is Euler's constant, the base of the natural logarithms.
307 Math.expm1() Experimental, JavaScript, Math, Method, Reference
The Math.expm1() function returns ex - 1, where x is the argument, and e the base of the natural logarithms.
308 Math.floor() JavaScript, Math, Method, Reference
The Math.floor() function returns the largest integer less than or equal to a given number.
309 Math.fround() Experimental, JavaScript, Math, Method, Reference
The Math.fround() function returns the nearest single precision float representation of a number.
310 Math.hypot() Experimental, JavaScript, Math, Method, Reference
The Math.hypot() function returns the square root of the sum of squares of its arguments, that is
311 Math.imul() Experimental, JavaScript, Math, Method, Reference
The Math.imul() function returns the result of the C-like 32-bit multiplication of the two parameters.
312 Math.log() JavaScript, Math, Method, Reference
The Math.log() function returns the natural logarithm (base e) of a number, that is
313 Math.log10() ECMAScript6, Experimental, JavaScript, Math, Method, Reference
The Math.log10() function returns the base 10 logarithm of a number, that is
314 Math.log1p() ECMAScript6, Experimental, JavaScript, Math, Method, Reference
The Math.log1p() function returns the natural logarithm (base e) of 1 + a number, that is
315 Math.log2() ECMAScript6, Experimental, JavaScript, Math, Method, Reference
The Math.log2() function returns the base 2 logarithm of a number, that is
316 Math.max() JavaScript, Math, Method, Reference
The Math.max() function returns the largest of zero or more numbers.
317 Math.min() JavaScript, Math, Method, Reference
The Math.min() function returns the smallest of zero or more numbers.
318 Math.pow() JavaScript, Math, Method, Reference
The Math.pow() function returns the base to the exponent power, that is, baseexponent.
319 Math.random() JavaScript, Math, Method, Reference
The Math.random() function returns a floating-point, pseudo-random number in the range [0, 1) that is, from 0 (inclusive) up to but not including 1 (exclusive), which you can then scale to your desired range. The implementation selects the initial seed to the random number generation algorithm; it cannot be chosen or reset by the user.
320 Math.round() JavaScript, Math, Method, Reference
The Math.round() function returns the value of a number rounded to the nearest integer.
321 Math.sign() Experimental, JavaScript, Math, Method, Reference
The Math.sign() function returns the sign of a number, indicating whether the number is positive, negative or zero.
322 Math.sin() JavaScript, Math, Method, Reference
The Math.sin() function returns the sine of a number.
323 Math.sinh() ECMAScript6, Experimental, JavaScript, Math, Method, Reference
The Math.sinh() function returns the hyperbolic sine of a number, that can be expressed using the constant e:
324 Math.sqrt() JavaScript, Math, Method, Reference
The Math.sqrt() function returns the square root of a number, that is
325 Math.tan() JavaScript, Math, Method, Reference
The Math.tan() function returns the tangent of a number.
326 Math.tanh() ECMAScript6, Experimental, JavaScript, Math, Method, Reference
The Math.tanh() function returns the hyperbolic tangent of a number, that is
327 Math.trunc() ECMAScript6, Experimental, JavaScript, Math, Method, Reference
The Math.trunc() function returns the integral part of a number by removing any fractional digits.
328 NaN JavaScript
The global NaN property is a value representing Not-A-Number.
329 Number JavaScript, Number, Reference
The Number JavaScript object is a wrapper object allowing you to work with numerical values. A Number object is created using the Number() constructor.
330 Number.EPSILON ECMAScript6, Experimental, JavaScript, Number, Property
The Number.EPSILON property represents the difference between one and the smallest value greater than one that can be represented as a Number.
331 Number.MAX_SAFE_INTEGER ECMAScript6, Experimental, JavaScript, Number, Property
The Number.MAX_SAFE_INTEGER constant represents the maximum safe integer in JavaScript (253 - 1).
332 Number.MAX_VALUE JavaScript, Number, Property
The Number.MAX_VALUE property represents the maximum numeric value representable in JavaScript.
333 Number.MIN_SAFE_INTEGER ECMAScript6, Experimental, JavaScript, Number, Property
The Number.MIN_SAFE_INTEGER constant represents the minimum safe integer in JavaScript (-(253 - 1)).
334 Number.MIN_VALUE JavaScript, Number, Property
The Number.MIN_VALUE property represents the smallest positive numeric value representable in JavaScript.
335 Number.NEGATIVE_INFINITY JavaScript, Number, Property
The Number.NEGATIVE_INFINITY property represents the negative Infinity value.
336 Number.NaN JavaScript, Number, Property
The Number.NaN property represents Not-A-Number. Equivalent of NaN.
337 Number.POSITIVE_INFINITY JavaScript, Number, Property
The Number.POSITIVE_INFINITY property represents the positive Infinity value.
338 Number.isFinite() Experimental, Expérimental, JavaScript, Method, Number, Reference, Réference, Référence
The Number.isFinite() method determines whether the passed value is a finite number.
339 Number.isInteger() Experimental, Expérimental, JavaScript, Method, Number, Reference, Réference, Référence
The Number.isInteger() method determines whether the passed value is an integer.
340 Number.isNaN() ECMAScript6, Experimental, Expérimental, JavaScript, Method, Number
The Number.isNaN() method determines whether the passed value is NaN. More robust version of the original global isNaN().
341 Number.isSafeInteger() ECMAScript6, Experimental, Expérimental, JavaScript, Method, Number
The Number.isSafeInteger() method determines whether the provided value is a number that is a safe integer. A safe integer is an integer that
342 Number.parseFloat() ECMAScript6, Experimental, JavaScript, Method, Number
The Number.parseFloat() method parses a string argument and returns a floating point number. This method behaves identically to the global function parseFloat() and is part of ECMAScript 6 (its purpose is modularization of globals).
343 Number.parseInt() ECMAScript6, Experimental, JavaScript, Method, Number
The Number.parseInt() method parses a string argument and returns an integer of the specified radix or base.
344 Number.prototype JavaScript, Number, Property, prototype
The Number.prototype property represents the prototype for the Number constructor.
345 Number.prototype.toExponential() JavaScript, Method, Number, prototype
The toExponential() method returns a string representing the Number object in exponential notation
346 Number.prototype.toFixed() JavaScript, Method, Number, prototype
The toFixed() method formats a number using fixed-point notation.
347 Number.prototype.toLocaleString() Internationalization, JavaScript, Method, Number, prototype
The toLocaleString() method returns a string with a language sensitive representation of this number.
348 Number.prototype.toPrecision() JavaScript, Method, Number, prototype
The toPrecision() method returns a string representing the Number object to the specified precision.
349 Number.prototype.toSource() JavaScript, Method, Non-standard, Number, prototype
The toSource() method returns a string representing the source code of the object.
350 Number.prototype.toString() JavaScript, Method, Number, prototype
The toString() method returns a string representing the specified Number object.
351 Number.prototype.valueOf() JavaScript, Method, Number, prototype
The valueOf() method returns the wrapped primitive value of a Number object.
352 Number.toInteger() JavaScript, Method, Non-standard, Number, Obsolete
The Number.toInteger() method used to evaluate the passed value and convert it to an integer, but its implementation has been removed.
353 Object Constructor, JavaScript, Object
The Object constructor creates an object wrapper.
354 Object.assign() ECMAScript6, Experimental, Expérimental, JavaScript, Method, Object, Reference, Référence, polyfill
The Object.assign() method is used to copy the values of all enumerable own properties from one or more source objects to a target object. It will return the target object.
355 Object.create() ECMAScript5, JavaScript, Method, Object, Reference, polyfill
The Object.create() method creates a new object with the specified prototype object and properties.
356 Object.defineProperties() ECMAScript5, JavaScript, JavaScript 1.8.5, Method, Object
The Object.defineProperties() method defines new or modifies existing properties directly on an object, returning the object.
357 Object.defineProperty() ECMAScript5, JavaScript, JavaScript 1.8.5, Method, Object
The Object.defineProperty() method defines a new property directly on an object, or modifies an existing property on an object, and returns the object.
358 Additional examples for Object.defineProperty Examples, JavaScript, Object
This page provides additional examples for Object.defineProperty().
359 Object.freeze() ECMAScript5, JavaScript, JavaScript 1.8.5, Method, Object
The Object.freeze() method freezes an object: that is, prevents new properties from being added to it; prevents existing properties from being removed; and prevents existing properties, or their enumerability, configurability, or writability, from being changed. In essence the object is made effectively immutable. The method returns the object being frozen.
360 Object.getOwnPropertyDescriptor() ECMAScript5, JavaScript, Method, Object
The Object.getOwnPropertyDescriptor() method returns a property descriptor for an own property (that is, one directly present on an object, not present by dint of being along an object's prototype chain) of a given object.
361 Object.getOwnPropertyNames() ECMAScript5, JavaScript, JavaScript 1.8.5, Method, Object, Reference
The Object.getOwnPropertyNames() method returns an array of all properties (enumerable or not) found directly upon a given object.
362 Object.getOwnPropertySymbols() ECMAScript6, Experimental, JavaScript, Method, Object
The Object.getOwnPropertySymbols() method returns an array of all symbol properties found directly upon a given object.
363 Object.getPrototypeOf() ECMAScript5, JavaScript, Method, Object
The Object.getPrototypeOf() method returns the prototype (i.e. the value of the internal [[Prototype]] property) of the specified object.
364 Object.is() Comparison, Condition, Conditional, ECMAScript6, Equality, JavaScript, Method, Object, equality
The Object.is() method determines whether two values are the same value.
365 Object.isExtensible() ECMAScript5, JavaScript, JavaScript 1.8.5, Method, Object
The Object.isExtensible() method determines if an object is extensible (whether it can have new properties added to it).
366 Object.isFrozen() ECMAScript5, JavaScript, JavaScript 1.8.5, Method, Object
The Object.isFrozen() determines if an object is frozen.
367 Object.isSealed() ECMAScript5, JavaScript, JavaScript 1.8.5, Method, Object
The Object.isSealed() method determines if an object is sealed.
368 Object.keys() ECMAScript5, JavaScript, JavaScript 1.8.5, Method, Object
The Object.keys() method returns an array of a given object's own enumerable properties, in the same order as that provided by a for...in loop (the difference being that a for-in loop enumerates properties in the prototype chain as well).
369 Object.observe() ECMAScript7, Experimental, Expérimental, JavaScript, Method, Object
The Object.observe() method is used for asynchronously observing the changes to an object. It provides a stream of changes in the order in which they occur.
370 Object.preventExtensions() ECMAScript5, JavaScript, JavaScript 1.8.5, Method, Object
The Object.preventExtensions() method prevents new properties from ever being added to an object (i.e. prevents future extensions to the object).
371 Object.prototype JavaScript, Object, Property
The Object.prototype property represents the Object prototype object.
372 Object.prototype.__count__ JavaScript, Object, Obsolete, Property, prototype
The __count__ property used to store the count of enumerable properties on the object, but it has been removed.
373 Object.prototype.__defineGetter__() JavaScript, Method, Non-standard, Object, prototype
The __defineGetter__ method binds an object's property to a function to be called when that property is looked up.
374 Object.prototype.__defineSetter__() JavaScript, Method, Non-standard, Object, prototype
The __defineSetter__ method binds an object's property to a function to be called when an attempt is made to set that property.
375 Object.prototype.__lookupGetter__() Deprecated, JavaScript, Method, Non-standard, Object, deprecated, prototype
The __lookupGetter__ method returns the function bound as a getter to the specified property.
376 Object.prototype.__lookupSetter__() Deprecated, JavaScript, Method, Non-standard, Object, deprecated, prototype
The __lookupSetter__ method returns the function bound as a setter to the specified property.
377 Object.prototype.__noSuchMethod__ JavaScript, Object, Obsolete, Property, prototype
The __noSuchMethod__ property references a function to be executed when a non-existent method is called on an object.
378 Object.prototype.__parent__ JavaScript, Object, Obsolete, Property, prototype
The __parent__ property used to point to an object's context, but it has been removed.
379 Object.prototype.__proto__ Deprecated, JavaScript, Object, Property, Reference, deprecated, prototype
The __proto__ property of Object.prototype is an accessor property (a getter function and a setter function) that exposes the internal [[Prototype]] (either an object or null) of the object through which it is accessed.
380 Object.prototype.constructor JavaScript, Object, Property, prototype
Returns a reference to the Object function that created the instance's prototype. Note that the value of this property is a reference to the function itself, not a string containing the function's name. The value is only read-only for primitive values such as 1true and "test".
381 Object.prototype.eval() JavaScript, Method, Object, Obsolete
The Object.eval() method used to evaluate a string of JavaScript code in the context of an object, however, this method has been removed.
382 Object.prototype.hasOwnProperty() JavaScript, Method, Object, prototype
The hasOwnProperty() method returns a boolean indicating whether the object has the specified property.
383 Object.prototype.isPrototypeOf() JavaScript, Method, Object, prototype
The isPrototypeOf() method tests for an object in another object's prototype chain.
384 Object.prototype.propertyIsEnumerable() JavaScript, Method, Object, prototype
The propertyIsEnumerable() method returns a Boolean indicating whether the specified property is enumerable.
385 Object.prototype.toLocaleString() JavaScript, Method, Object, prototype
The toLocaleString() method returns a string representing the object. This method is meant to be overridden by derived objects for locale-specific purposes.
386 Object.prototype.toSource() JavaScript, Method, Non-standard, Object, prototype
The toSource() method returns a string representing the source code of the object.
387 Object.prototype.toString() JavaScript, Method, Object, prototype
The toString() method returns a string representing object.
388 Object.prototype.unwatch() JavaScript, Method, Non-standard, Object, Reference, prototype
The unwatch() method removes a watchpoint set with the watch() method.
389 Object.prototype.valueOf() JavaScript, Method, Object, prototype
The valueOf() method returns the primitive value of the specified object.
390 Object.prototype.watch() JavaScript, Method, Non-standard, Object, prototype
The watch() method watches for a property to be assigned a value and runs a function when that occurs.
391 Object.seal() ECMAScript5, JavaScript, JavaScript 1.8.5, Method, Object
The Object.seal() method seals an object, preventing new properties from being added to it and marking all existing properties as non-configurable. Values of present properties can still be changed as long as they are writable.
392 Object.setPrototypeOf() ECMAScript6, Experimental, Expérimental, JavaScript, Method, Object
The Object.setPrototypeOf() method sets the prototype (i.e., the internal [[Prototype]] property) of a specified object to another object or null.
393 Object.unobserve() ECMAScript7, Experimental, JavaScript, Method, Object
The Object.unobserve() method is used to remove observers set by Object.observe().
394 ParallelArray JavaScript, Obsolete, ParallelArray
The goal of ParallelArray was to enable data-parallelism in web applications. The higher-order functions available on ParallelArray attempted to execute in parallel, though they may fall back to sequential execution if necessary. To ensure that your code executes in parallel, it is suggested that the functions should be limited to the parallelizable subset of JS that Firefox supports.
395 Promise ECMAScript6, Experimental, JavaScript, Promise
The Promise object is used for deferred and asynchronous computations. A Promise represents an operation that hasn't completed yet, but is expected to in the future.
396 Promise.all() ECMAScript6, Experimental, JavaScript, Method, Promise
The Promise.all(iterable) method returns a promise that resolves when all of the promises in the iterable argument have resolved.
397 Promise.prototype Experimental, JavaScript, Promise, Property
The Promise.prototype property represents the prototype for the Promise constructor.
398 Promise.prototype.catch() ECMAScript6, Experimental, JavaScript, Method, Promise, prototype
The catch() method returns a Promise and deals with rejected cases only. It behaves the same as calling Promise.prototype.then(undefined, onRejected).
399 Promise.prototype.then() ECMAScript6, Experimental, JavaScript, Method, Promise, prototype
The then() method returns a Promise. It takes two arguments, both are callback functions for the success and failure cases of the Promise.
400 Promise.race() ECMAScript6, Experimental, JavaScript, Method, Promise
The Promise.race(iterable) method returns a promise that resolves or rejects as soon as one of the promises in the iterable resolves or rejects, with the value or reason from that promise.
401 Promise.reject() ECMAScript6, Experimental, Expérimental, JavaScript, Method, Promise
The Promise.reject(reason) method returns a Promise object that is rejected with the given reason.
402 Promise.resolve() ECMAScript6, Experimental, Expérimental, JavaScript, Method, Promise
The Promise.resolve(value) method returns a Promise object that is resolved with the given value. If the value is a thenable (i.e. has a then method), the returned promise will "follow" that thenable, adopting its eventual state; otherwise the returned promise will be fulfilled with the value.
403 Proxy ECMAScript6, Experimental, Expérimental, JavaScript, Proxy
The Proxy object is used to define custom behavior for fundamental operations (e.g. property lookup, assignment, enumeration, function invocation, etc).
404 Proxy handler ECMAScript6, Experimental, JavaScript, Proxy
The proxy's handler object is a placeholder object which contains traps for proxies.
405 handler.apply() ECMAScript6, Experimental, JavaScript, Method, Proxy
The handler.apply() method is a trap for a function call.
406 handler.construct() ECMAScript6, Experimental, JavaScript, Method, Proxy
The handler.construct() method is a trap for the new operator.
407 handler.defineProperty() ECMAScript6, Experimental, JavaScript, Method, Proxy
The handler.defineProperty() method is a trap for Object.defineProperty().
408 handler.deleteProperty() ECMAScript6, Experimental, JavaScript, Method, Proxy
The handler.deleteProperty() method is a trap for the delete operator.
409 handler.enumerate() ECMAScript6, Experimental, JavaScript, Method, Proxy
The handler.enumerate() method is a trap for for...in statements.
410 handler.get() ECMAScript6, Experimental, JavaScript, Method, Proxy
The handler.get() method is a trap for getting a property value.
411 handler.getOwnPropertyDescriptor() ECMAScript6, Experimental, JavaScript, Method, Proxy
The handler.getOwnPropertyDescriptor() method is a trap for Object.getOwnPropertyDescriptor().
412 handler.getPrototypeOf() ECMAScript6, Experimental, JavaScript, Method, Proxy
The handler.getPrototypeOf() method is a trap for the [[GetPrototypeOf]] internal method.
413 handler.has() ECMAScript6, Experimental, JavaScript, Method, Proxy
The handler.has() method is a trap for the in operator.
414 handler.isExtensible() ECMAScript6, Experimental, JavaScript, Method, Proxy
The handler.isExtensible() method is a trap for Object.isExtensible().
415 handler.ownKeys() ECMAScript6, Experimental, JavaScript, Method, Proxy
The handler.ownKeys() method is a trap for Object.getOwnPropertyNames().
416 handler.preventExtensions() ECMAScript6, Experimental, JavaScript, Method, Proxy
The handler.preventExtensions() method is a trap for Object.preventExtensions().
417 handler.set() ECMAScript6, Experimental, JavaScript, Method, Proxy
The handler.set() method is a trap for setting a property value.
418 handler.setPrototypeOf() ECMAScript6, Experimental, JavaScript, Method, NeedsExample, Proxy
The handler.setPrototypeOf() method is a trap for Object.setPrototypeOf().
419 Proxy.revocable() ECMAScript6, Experimental, JavaScript, Method, Proxy
The Proxy.revocable() method is used to create a revocable Proxy object.
420 RangeError Error, JavaScript, Object, RangeError
The RangeError object indicates an error when a value is not in the set or range of allowed values.
421 RangeError.prototype Error, JavaScript, Property, RangeError, prototype
The RangeError.prototype property represents the prototype the RangeError constructor.
422 ReferenceError Error, JavaScript, Object, Reference, ReferenceError
The ReferenceError object represents an error when a non-existent variable is referenced.
423 ReferenceError.prototype Error, JavaScript, Property, ReferenceError, prototype
The ReferenceError.prototype property represents the prototype for the ReferenceError constructor.
424 Reflect ECMAScript6, Experimental, JavaScript, Reflect
Reflect is a built-in object that provides methods for interceptable JavaScript operations. The methods are the same as those of the proxy handlers. It is not a function object.
425 Reflect.apply() ECMAScript6, Experimental, JavaScript, Method, Reflect
The static Reflect.appy() method calls a target function with arguments as specified.
426 Reflect.construct() ECMAScript6, Experimental, JavaScript, Method, Reflect
The static Reflect.construct() method acts like the new operator as a function. It is equivalent to calling new target(...args).
427 Reflect.defineProperty() ECMAScript6, Experimental, JavaScript, Method, Reflect
The static Reflect.defineProperty() method is like Object.defineProperty() but returns a Boolean.
428 RegExp Constructor, JavaScript, Reference, RegExp, Regular Expressions
The RegExp constructor creates a regular expression object for matching text with a pattern.
429 RegExp.$1-$9 JavaScript, Non-standard, Property, Read-only, Reference, RegExp, Regular Expressions
The non-standard $1, $2, $3, $4, $5, $6, $7, $8, $9 properties are static and read-only properties of regular expressions that contain parenthesized substring matches.
430 RegExp.input ($_) JavaScript, Non-standard, Property, Reference, RegExp, Regular Expressions
The non-standard input property is a static property of regular expressions that contains the string against which a regular expression is matched. RegExp.$_ is an alias for this property.
431 RegExp.lastIndex JavaScript, Property, Reference, RegExp, Regular Expressions
The lastIndex is a read/write integer property of regular expressions that specifies the index at which to start the next match.
432 RegExp.lastMatch ($&) JavaScript, Non-standard, Property, Read-only, Reference, RegExp, Regular Expressions
The non-standard lastMatch property is a static and read-only property of regular expressions that contains the last matched characters. RegExp.$& is an alias for this property.
433 RegExp.lastParen ($+) JavaScript, Non-standard, Property, Read-only, Reference, RegExp, Regular Expressions
The non-standard lastParen property is a static and read-only property of regular expressions that contains the last parenthesized substring match, if any. RegExp.$+ is an alias for this property.
434 RegExp.leftContext ($`) JavaScript, Non-standard, Property, Read-only, Reference, RegExp, Regular Expressions
The non-standard leftContext property is a static and read-only property of regular expressions that contains the substring preceding the most recent match. RegExp.$` is an alias for this property.
435 RegExp.prototype JavaScript, Property, Reference, RegExp, prototype
The RegExp.prototype property represents the prototype object for the RegExp constructor.
436 RegExp.prototype.compile() Deprecated, JavaScript, Method, Reference, RegExp, Regular Expressions, deprecated, prototype
The deprecated compile() method is used to (re-)compile a regular expression during execution of a script. It is basically the same as the RegExp constructor.
437 RegExp.prototype.exec() JavaScript, Method, Reference, RegExp, Regular Expressions, prototype
The exec() method executes a search for a match in a specified string. Returns a result array, or null.
438 RegExp.prototype.flags ECMAScript6, Experimental, JavaScript, Property, Reference, RegExp, Regular Expressions, prototype
The flags property returns a string consisting of the flags of the current regular expression object.
439 RegExp.prototype.global JavaScript, Property, Reference, RegExp, Regular Expressions, prototype
The global property indicates whether or not the "g" flag is used with the regular expression. global is a read-only property of an individual regular expression instance.
440 RegExp.prototype.ignoreCase JavaScript, Property, Reference, RegExp, Regular Expressions, prototype
The ignoreCase property indicates whether or not the "i" flag is used with the regular expression. ignoreCase is a read-only property of an individual regular expression instance.
441 RegExp.prototype.multiline JavaScript, Property, Reference, RegExp, Regular Expressions, prototype
The multiline property indicates whether or not the "m" flag is used with the regular expression. multiline is a read-only property of an individual regular expression instance.
442 RegExp.prototype.source JavaScript, Property, Reference, RegExp, Regular Expressions, prototype
The source property returns a String containing the source text of the regexp object, and it doesn't contain the two forward slashes on both sides and any flags.
443 RegExp.prototype.sticky ECMAScript6, Experimental, JavaScript, Property, Reference, RegExp, Regular Expressions, prototype
The sticky property reflects whether or not the search is sticky (searches in strings only from the index indicated by the lastIndex property of this regular expression). sticky is a read-only property of an individual regular expression object.
444 RegExp.prototype.test() JavaScript, Method, Reference, RegExp, Regular Expressions, prototype
The test() method executes a search for a match between a regular expression and a specified string. Returns true or false.
445 RegExp.prototype.toSource() JavaScript, Method, Non-standard, Reference, RegExp, Regular Expressions, prototype
The toSource() method returns a string representing the source code of the object.
446 RegExp.prototype.toString() JavaScript, Method, Reference, RegExp, Regular Expressions, prototype
The toString() method returns a string representing the regular expression.
447 RegExp.prototype.unicode ECMAScript6, Experimental, JavaScript, Property, Reference, RegExp, Regular Expressions, prototype
The unicode property indicates whether or not the "u" flag is used with the regular expression. unicode is a read-only property of an individual regular expression instance.
448 RegExp.rightContext ($') JavaScript, Non-standard, Property, Read-only, Reference, RegExp, Regular Expressions
The non-standard rightContext property is a static and read-only property of regular expressions that contains the substring following the most recent match. RegExp.$' is an alias for this property.
449 SIMD Experimental, JavaScript, SIMD
SIMD (pronounced "sim-dee") is short for Single Instruction/Multiple Data which is one classification of computer architectures. SIMD operations perform the same computation on multiple data points resulting in data level parallelism and thus performance gains, for example for 3D graphics and video processing, physics simulations or cryptography, and other domains.
450 SIMD.%type%.abs() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.abs() method returns a new SIMD data type with absolute values. This operation exists only on floating point SIMD types.
451 SIMD.%type%.add() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.add() method returns a new instance with the lane values added (a + b).
452 SIMD.%type%.and() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.and() method returns a new instance with the logical AND of the lane values (a & b). This operation exists only on integer and boolean SIMD types.
453 SIMD.%type%.bool() Experimental, JavaScript, Method, SIMD
The SIMD.%type%.bool() constructor is used to create a custom selection mask. Masking (or "branching") the lanes is useful as you can't operate on a fraction of data in SIMD data types. However, with masks and the select function, you can branch and merge vectors to assemble the result vector you need.
454 SIMD.%type%.check() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.check() method returns a SIMD data type if the parameter is a valid SIMD data type and the same as %type%. Otherwise, a TypeError is thrown.
455 SIMD.%type%.div() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.div() method returns a new instance with the lane values divided (a / b). This function is defined only on floating point SIMD types.
456 SIMD.%type%.equal() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.equal() method returns a selection mask with values depending on a strict equality comparison (a === b) in each lane.
457 SIMD.%type%.extractLane() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.extractLane() method returns the value of a given lane.
458 SIMD.%type%.fromFloat32x4() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.fromFloat32x4() method creates a new SIMD data type with a float conversion from a Float32x4.
459 SIMD.%type%.fromFloat32x4Bits() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.fromFloat32x4Bits() method creates a new SIMD data type with a bit-wise copy from a Float32x4.
460 SIMD.%type%.fromFloat64x2() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.fromFloat64x2() method creates a new SIMD data type with a float conversion from a Float64x2.
461 SIMD.%type%.fromFloat64x2Bits() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.fromFloat64x2Bits() method creates a new SIMD data type with a bit-wise copy from a Float64x2.
462 SIMD.%type%.fromInt16x8Bits() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.fromInt16x8Bits() method creates a new SIMD data type with a bit-wise copy from an int16x8.
463 SIMD.%type%.fromInt32x4() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.fromInt32x4() method creates a new SIMD data type with a float conversion from an Int32x4.
464 SIMD.%type%.fromInt32x4Bits() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.fromInt32x4Bits() method creates a new SIMD data type with a bit-wise copy from an Int32x4.
465 SIMD.%type%.fromInt8x16Bits() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.fromInt8x16Bits() method creates a new SIMD data type with a bit-wise copy from an Int8x16.
466 SIMD.%type%.greaterThan() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.greaterThan() method returns a selection mask with values depending on a greater-than comparison (a > b) in each lane.
467 SIMD.%type%.greaterThanOrEqual() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.greaterThanOrEqual() method returns a selection mask with values depending on a greater-than-or-equal comparison (a >= b) in each lane.
468 SIMD.%type%.lessThan() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.lessThan() method returns a selection mask with values depending on a less-than comparison (a < b) in each lane.
469 SIMD.%type%.lessThanOrEqual() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.lessThanOrEqual() method returns a selection mask with values depending on a less-than-or-equal comparison (a <= b) in each lane.
470 SIMD.%type%.load() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.load() methods create a new SIMD data type with the lane values loaded from a typed array.
471 SIMD.%type%.max() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.max() method returns a new instance with the maximum lane values of two SIMD types (Math.max(a, b)).
472 SIMD.%type%.maxNum() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.maxNum() method returns a new instance with the maximum lane values of two SIMD types (Math.max(a, b)) preferring numbers over NaN.
473 SIMD.%type%.min() Experimental, Expérimental, JavaScript, Method, SIMD
The static SIMD.%type%.min() method returns a new instance with the minimum lane values of two SIMD types (Math.min(a, b)).
474 SIMD.%type%.minNum() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.minNum() method returns a new instance with the minimum lane values of two SIMD types (Math.min(a, b)) preferring numbers over NaN.
475 SIMD.%type%.mul() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.mul() method returns a new instance with the lane values multiplied (a * b).
476 SIMD.%type%.neg() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.mul() method returns a new instance with the lane values negated.
477 SIMD.%type%.not() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.not() method returns a new instance with the bitwise logical NOT of the lane values (~a). This operation exists only on integer and boolean SIMD types.
478 SIMD.%type%.notEqual() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.notEqual() method returns a selection mask with values depending on an inequality comparison (a != b) in each lane.
479 SIMD.%type%.or() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.or() method returns a new instance with the logical OR of the lane values (a | b). This operation exists only on integer and boolean SIMD types.
480 SIMD.%type%.prototype.toSource() JavaScript, Method, Non-standard, SIMD, prototype
The non-standard SIMD.%type%.toSource() method returns a string representing the source code of the object.
481 SIMD.%type%.reciprocalApproximation() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.reciprocalApproximation() method returns a new instance with an approximation of the reciprocal lane values (1 / x).
482 SIMD.%type%.reciprocalSqrtApproximation() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.reciprocalSqrtApproximation() method returns a new instance with an approximation of the reciprocal value (1 / x) of the square root (Math.sqrt()) of the lane values.
483 SIMD.%type%.replaceLane() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.replaceLane() method returns a new SIMD data type with the given lane value replaced.
484 SIMD.%type%.select() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.select() method creates a new integer SIMD data type with the lane values being a selection match from a selector mask.
485 SIMD.%type%.selectBits() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.selectBits() method creates a new integer SIMD data type with the lane values being a selection match of bits depending on the selector mask.
486 SIMD.%type%.shiftLeftByScalar() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.shiftLeftByScalar() method returns a new instance with the lane values shifted left by a given bit count (a << bits).
487 SIMD.%type%.shiftRightArithmeticByScalar() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.shiftRightArithmeticByScalar() method returns a new instance with the lane values shifted right (arithmetic) by a given bit count (a >> bits).
488 SIMD.%type%.shiftRightLogicalByScalar() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.shiftRightLogicalByScalar() method returns a new instance with the lane values shifted right (logical) by a given bit count (a >>> bits).
489 SIMD.%type%.shuffle() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.shuffle() method creates a new SIMD data type instance with the lane values shuffled.
490 SIMD.%type%.splat() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.splat() method creates a new SIMD data type with all lanes set to a given value.
491 SIMD.%type%.sqrt() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.sqrt() method returns a new instance with the square root of the lane values (see also Math.sqrt() for the same scalar function).
492 SIMD.%type%.store() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.store() methods store a SIMD data type into a typed array.
493 SIMD.%type%.sub() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.sub() method returns a new instance with the lane values subtracted (a - b).
494 SIMD.%type%.swizzle() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.swizzle() method creates a new SIMD data type instance with the lane values swizzled (re-ordered).
495 SIMD.%type%.xor() Experimental, JavaScript, Method, SIMD
The static SIMD.%type%.xor() method returns a new instance with the logical XOR of the lane values (a ^ b).
496 SIMD.Float32x4 Experimental, JavaScript, SIMD
The SIMD.Float32x4 data type is a 128-bit vector divided into 4 lanes storing single precision floating point values.
497 SIMD.Float64x2 Experimental, JavaScript, SIMD
The SIMD.Float64x2 data type is a 128-bit vector divided into 2 lanes storing double precision floating point values.
498 SIMD.Int16x8 Experimental, JavaScript, SIMD
The SIMD.Int16x8 data type is a 128-bit vector divided into 8 lanes storing 16-bit signed integer values.
499 SIMD.Int32x4 Experimental, JavaScript, SIMD
The SIMD.Int32x4 data type is a 128-bit vector divided into 4 lanes storing 32-bit signed integer values.
500 SIMD.Int8x16 Experimental, JavaScript, SIMD
The SIMD.Int8x16 data type is a 128-bit vector divided into 16 lanes storing 8-bit signed integer values.
501 Set ECMAScript6, Experimental, JavaScript, set
The Set object lets you store unique values of any type, whether primitive values or object references.
502 Set.prototype ECMAScript6, Experimental, JavaScript, Property, set
The Set.prototype property represents the prototype for the Set constructor.
503 Set.prototype.add() ECMAScript6, Experimental, JavaScript, Method, prototype, set
The add() method appends a new element with a specified value to the end of a Set object.
504 Set.prototype.clear() ECMAScript6, Experimental, JavaScript, Method, prototype, set
The clear() method removes all elements from a Set object.
505 Set.prototype.delete() ECMAScript6, Experimental, JavaScript, Method, prototype, set
The delete() method removes the specified element from a Set object.
506 Set.prototype.entries() ECMAScript6, Experimental, Iterator, JavaScript, Method, prototype, set
The entries() method returns a new Iterator object that contains an array of [value, value] for each element in the Set object, in insertion order. For Set objects there is no key like in Map objects. However, to keep the API similar to the Map object, each entry has the same value for its key and value here, so that an array [value, value] is returned.
507 Set.prototype.forEach() ECMAScript6, Experimental, JavaScript, Method, prototype, set
The forEach() method executes a provided function once per each value in the Set object, in insertion order.
508 Set.prototype.has() ECMAScript6, Experimental, JavaScript, Method, prototype, set
The has() method returns a boolean indicating whether an element with the specified value exists in a Set object or not.
509 Set.prototype.size ECMAScript6, Experimental, JavaScript, Property, prototype, set
The size accessor property returns the number of elements in a Set object.
510 Set.prototype.values() ECMAScript6, Experimental, Iterator, JavaScript, Method, prototype, set
The values() method returns a new Iterator object that contains the values for each element in the Set object in insertion order.
511 Set.prototype[@@iterator]() ECMAScript6, Experimental, Iterator, JavaScript, Method, Reference, prototype, set
The initial value of the @@iterator property is the same function object as the initial value of the values property.
512 get Set[@@species] ECMAScript6, Experimental, JavaScript, Property, set
The Set[@@species] accessor property returns the Set constructor.
513 StopIteration Deprecated, JavaScript, Legacy Iterator, Non-standard, Reference, StopIteration, deprecated
The StopIteration object is used to tell the end of the iteration in the legacy iterator protocol.
514 String ECMAScript6, JavaScript, Reference, String
The String global object is a constructor for strings, or a sequence of characters.
515 String.fromCharCode() JavaScript, Method, Reference, String, Unicode
The static String.fromCharCode() method returns a string created by using the specified sequence of Unicode values.
516 String.fromCodePoint() ECMAScript6, Experimental, JavaScript, Method, Reference, String
The static String.fromCodePoint() method returns a string created by using the specified sequence of code points.
517 String.length JavaScript, Property, Reference, String, prototype
The length property represents the length of a string.
518 String.prototype JavaScript, Property, Reference, String, prototype
The String.prototype property represents the String prototype object.
519 String.prototype.anchor() HTML wrapper methods, JavaScript, Method, Reference, String, prototype
The anchor() method creates an <a> HTML anchor element that is used as a hypertext target.
520 String.prototype.big() Deprecated, HTML wrapper methods, JavaScript, Method, Reference, String, deprecated, prototype
The big() method creates a <big> HTML element that causes a string to be displayed in a big font.
521 String.prototype.blink() Deprecated, HTML wrapper methods, JavaScript, Method, Reference, String, deprecated, prototype
The blink() method creates a <blink> HTML element that causes a string to blink.
522 String.prototype.bold() Deprecated, HTML wrapper methods, JavaScript, Method, Reference, String, deprecated, prototype
The bold() method creates a <b> HTML element that causes a string to be displayed as bold.
523 String.prototype.charAt() JavaScript, Method, Reference, String, prototype
The charAt() method returns the specified character from a string.
524 String.prototype.charCodeAt() JavaScript, Method, Reference, String, Unicode
The charCodeAt() method returns the numeric Unicode value of the character at the given index (except for unicode codepoints > 0x10000).
525 String.prototype.codePointAt() ECMAScript6, Experimental, JavaScript, Method, Reference, String, prototype
The codePointAt() method returns a non-negative integer that is the UTF-16 encoded code point value.
526 String.prototype.concat() JavaScript, Method, Reference, String, prototype
The concat() method combines the text of two or more strings and returns a new string.
527 String.prototype.endsWith() Experimental, JavaScript, Method, Reference, String, prototype
The endsWith() method determines whether a string ends with the characters of another string, returning true or false as appropriate.
528 String.prototype.fixed() Deprecated, HTML wrapper methods, JavaScript, Method, Reference, String, deprecated, prototype
The fixed() method creates a <tt> HTML element that causes a string to be displayed in fixed-pitch font.
529 String.prototype.fontcolor() Deprecated, HTML wrapper methods, JavaScript, Method, Reference, String, deprecated, prototype
The fontcolor() method creates a <font> HTML element that causes a string to be displayed in the specified font color.
530 String.prototype.fontsize() Deprecated, HTML wrapper methods, JavaScript, Method, Reference, String, deprecated, prototype
The fontsize() method creates a <font> HTML element that causes a string to be displayed in the specified font size.
531 String.prototype.includes() Experimental, Expérimental, JavaScript, Method, Reference, Référence, String, prototype
The includes() method determines whether one string may be found within another string, returning true or false as appropriate.
532 String.prototype.indexOf() JavaScript, Method, Reference, String, prototype
The indexOf() method returns the index within the calling String object of the first occurrence of the specified value, starting the search at fromIndex. Returns -1 if the value is not found.
533 String.prototype.italics() Deprecated, HTML wrapper methods, JavaScript, Method, String, deprecated, prototype
The italics() method creates an <i> HTML element that causes a string to be italic.
534 String.prototype.lastIndexOf() JavaScript, Method, Reference, String, prototype
The lastIndexOf() method returns the index within the calling String object of the last occurrence of the specified value, or -1 if not found. The calling string is searched backward, starting at fromIndex.
535 String.prototype.link() HTML wrapper methods, JavaScript, Method, Reference, String, prototype
The link() method creates an <a> HTML element that causes a string to be displayed as a hypertext link to another URL.
536 String.prototype.localeCompare() Internationalization, JavaScript, Method, Reference, String, prototype
The localeCompare() method returns a number indicating whether a reference string comes before or after or is the same as the given string in sort order.
537 String.prototype.match() JavaScript, Method, Reference, Regular Expressions, String, prototype
The match() method retrieves the matches when matching a string against a regular expression.
538 String.prototype.normalize() ECMAScript6, Experimental, JavaScript, Method, Reference, String, Unicode, prototype
The normalize() method returns the Unicode Normalization Form of a given string (if the value isn't a string, it will be converted to one first).
539 String.prototype.quote() JavaScript, Method, Obsolete, Reference, String, prototype
The non-standard quote() method returns a copy of the string, replacing various special characters in the string with their escape sequences and wrapping the result in double-quotes (").
540 String.prototype.repeat() ECMAScript6, Experimental, JavaScript, Method, Reference, String, prototype
The repeat() method constructs and returns a new string which contains the specified number of copies of the string on which it was called, concatenated together.
541 String.prototype.replace() JavaScript, Method, Reference, Regular Expressions, String, prototype
The replace() method returns a new string with some or all matches of a pattern replaced by a replacement. The pattern can be a string or a RegExp, and the replacement can be a string or a function to be called for each match.
542 String.prototype.search() JavaScript, Method, Reference, Regular Expressions, String, prototype
The search() method executes a search for a match between a regular expression and this String object.
543 String.prototype.slice() JavaScript, Method, Reference, String, prototype
The slice() method extracts a section of a string and returns a new string.
544 String.prototype.small() Deprecated, HTML wrapper methods, JavaScript, Method, Reference, String, deprecated, prototype
The small() method creates a <small> HTML element that causes a string to be displayed in a small font.
545 String.prototype.split() JavaScript, Method, Reference, Regular Expressions, String, prototype
The split() method splits a String object into an array of strings by separating the string into substrings.
546 String.prototype.startsWith() ECMAScript6, Experimental, Expérimental, JavaScript, Method, Reference, String, prototype
The startsWith() method determines whether a string begins with the characters of another string, returning true or false as appropriate.
547 String.prototype.strike() Deprecated, HTML wrapper methods, JavaScript, Method, String, deprecated, prototype
The strike() method creates a <strike> HTML element that causes a string to be displayed as struck-out text.
548 String.prototype.sub() Deprecated, HTML wrapper methods, JavaScript, Method, String, deprecated, prototype
The sub() method creates a <sub> HTML element that causes a string to be displayed as subscript.
549 String.prototype.substr() JavaScript, Method, Reference, String, prototype
The substr() method returns the characters in a string beginning at the specified location through the specified number of characters.
550 String.prototype.substring() JavaScript, Method, Reference, String, prototype
The substring() method returns a subset of a string between one index and another, or through the end of the string.
551 String.prototype.sup() Deprecated, HTML wrapper methods, JavaScript, Method, Reference, String, deprecated, prototype
The sup() method creates a <sup> HTML element that causes a string to be displayed as superscript.
552 String.prototype.toLocaleLowerCase() Internationalization, JavaScript, Method, Reference, String, prototype
The toLocaleLowerCase() method returns the calling string value converted to lower case, according to any locale-specific case mappings.
553 String.prototype.toLocaleUpperCase() Internationalization, JavaScript, Method, Reference, String, prototype
The toLocaleUpperCase() method returns the calling string value converted to upper case, according to any locale-specific case mappings.
554 String.prototype.toLowerCase() JavaScript, Method, Reference, String, prototype
The toLowerCase() method returns the calling string value converted to lowercase.
555 String.prototype.toSource() JavaScript, Method, Non-standard, Reference, String, prototype
The toSource() method returns a string representing the source code of the object.
556 String.prototype.toString() JavaScript, Method, Reference, String, prototype
The toString() method returns a string representing the specified object.
557 String.prototype.toUpperCase() JavaScript, Method, Reference, String, prototype
The toUpperCase() method returns the calling string value converted to uppercase.
558 String.prototype.trim() ECMAScript5, JavaScript, Method, Reference, String, prototype
The trim() method removes whitespace from both ends of a string. Whitespace in this context is all the whitespace characters (space, tab, no-break space, etc.) and all the line terminator characters (LF, CR, etc.).
559 String.prototype.trimLeft() JavaScript, Method, Non-standard, Reference, String, prototype
The trimLeft() method removes whitespace from the left end of a string.
560 String.prototype.trimRight() JavaScript, Method, Non-standard, Reference, String, prototype
The trimRight() method removes whitespace from the right end of a string.
561 String.prototype.valueOf() JavaScript, Method, Reference, String, prototype
The valueOf() method returns the primitive value of a String object.
562 String.prototype[@@iterator]() ECMAScript6, Experimental, Iterator, JavaScript, Method, Reference, String, prototype
The [@@iterator]() method returns a new Iterator object that iterates over the code points of a String value, returning each code point as a String value.
563 String.raw() ECMAScript6, JavaScript, Method, Reference, String
The static String.raw() method is a tag function of template strings, like the r prefix in Python or the @ prefix in C# for string literals, this function is used to get the raw string form of template strings (that is, the original, uninterpreted text).
564 Symbol ECMAScript6, Experimental, Expérimental, JavaScript, Symbol
A symbol is a unique and immutable data type and may be used as an identifier for object properties. The symbol object is an implicit object wrapper for the symbol primitive data type.
565 Symbol.for() ECMAScript6, Experimental, Expérimental, JavaScript, Method, Symbol
The Symbol.for(key) method searches for existing symbols in a runtime-wide symbol registry with the given key and returns it if found. Otherwise a new symbol gets created in the global symbol registry with this key.
566 Symbol.iterator ECMAScript6, Experimental, Expérimental, JavaScript, Property, Symbol
The Symbol.iterator well-known symbol specifies the default iterator for an object. Used by for...of.
567 Symbol.keyFor() ECMAScript6, Experimental, Expérimental, JavaScript, Method, Symbol
The Symbol.keyFor(sym) method retrieves a shared symbol key from the global symbol registry for the given symbol.
568 Symbol.match ECMAScript6, Experimental, Expérimental, JavaScript, Property, Symbol
The Symbol.match well-known symbol specifies the matching of a regular expression against a string. This function is called by the String.prototype.match() method.
569 Symbol.prototype Experimental, Expérimental, JavaScript, Property, Symbol
The Symbol.prototype property represents the prototype for the Symbol constructor.
570 Symbol.prototype.toSource() JavaScript, Method, Non-standard, Symbol, prototype
The toSource() method returns a string representing the source code of the object.
571 Symbol.prototype.toString() ECMAScript6, Experimental, Expérimental, JavaScript, Method, Symbol, prototype
The toString() method returns a string representing the specified Symbol object.
572 Symbol.prototype.valueOf() ECMAScript6, Experimental, Expérimental, JavaScript, Method, Symbol, prototype
The valueOf() method returns the primitive value of a Symbol object.
573 Symbol.species ECMAScript6, Experimental, Expérimental, JavaScript, Property, Symbol
The Symbol.species well-known symbol specifies a function valued property that is the constructor function that is used to create derived objects.
574 SyntaxError Error, JavaScript, Object, Reference, SyntaxError
The SyntaxError object represents an error when trying to interpret syntactically invalid code.
575 SyntaxError.prototype Error, JavaScript, Property, SyntaxError, prototype
The SyntaxError.prototype property represents the prototype for the SyntaxError constructor.
576 TypeError Error, JavaScript, Object, Reference, TypeError
The TypeError object represents an error when a value is not of the expected type.
577 TypeError.prototype Error, JavaScript, Property, TypeError, prototype
The TypeError.prototype property represents the prototype for the TypeError constructor.
578 TypedArray JavaScript, TypedArray, TypedArrays
A TypedArray object describes an array-like view of an underlying binary data buffer. There is no global property named TypedArray, nor is there a directly visible TypedArray constructor.  Instead, there are a number of different global properties, whose values are typed array constructors for specific element types, listed below. On the following pages you will find common properties and methods that can be used with any typed array containing elements of any type.
579 TypedArray.BYTES_PER_ELEMENT JavaScript, Property, TypedArray, TypedArrays
The TypedArray.BYTES_PER_ELEMENT property represents the size in bytes of each element in an typed array.
580 TypedArray.from() ECMAScript6, JavaScript, Method, TypedArray, TypedArrays
The TypedArray.from() method creates a new typed array from an array-like or iterable object. This method is nearly the same as Array.from().
581 TypedArray.name JavaScript, Property, TypedArray, TypedArrays
The TypedArray.name property represents a string value of the typed array constructor name.
582 TypedArray.of() ECMAScript6, JavaScript, Method, TypedArray, TypedArrays
The TypedArray.of() method creates a new typed array with a variable number of arguments. This method is nearly the same as Array.of().
583 TypedArray.prototype JavaScript, Property, TypedArray, TypedArrays
The TypedArray.prototype property represents the prototype for TypedArray constructors.
584 TypedArray.prototype.buffer JavaScript, Property, TypedArray, TypedArrays, prototype
The buffer accessor property represents the ArrayBuffer referenced by a TypedArray at construction time.
585 TypedArray.prototype.byteLength JavaScript, Property, TypedArray, TypedArrays, prototype
The byteLength accessor property represents the length (in bytes) of a typed array from the start of its ArrayBuffer.
586 TypedArray.prototype.byteOffset JavaScript, Property, TypedArray, TypedArrays, prototype
The byteOffset accessor property represents the offset (in bytes) of a typed array from the start of its ArrayBuffer.
587 TypedArray.prototype.copyWithin() JavaScript, Method, TypedArray, TypedArrays, prototype
The copyWithin() method copies the sequence of array elements within the array to the position starting at target. The copy is taken from the index positions of the second and third arguments start and end. The end argument is optional and defaults to the length of the array. This method has the same algorithm as Array.prototype.copyWithin. TypedArray is one of the typed array types here.
588 TypedArray.prototype.entries() ECMAScript6, Iterator, JavaScript, Method, Reference, TypedArray, TypedArrays, prototype
The entries() method returns a new Array Iterator object that contains the key/value pairs for each index in the array.
589 TypedArray.prototype.every() ECMAScript6, JavaScript, Method, TypedArray, TypedArrays, prototype
The every() method tests whether all elements in the typed array pass the test implemented by the provided function. This method has the same algorithm as Array.prototype.every(). TypedArray is one of the typed array types here.
590 TypedArray.prototype.fill() ECMAScript6, JavaScript, Method, TypedArray, TypedArrays, prototype
The fill() method fills all the elements of a typed array from a start index to an end index with a static value. This method has the same algorithm as Array.prototype.fill(). TypedArray is one of the typed array types here.
591 TypedArray.prototype.filter() ECMAScript6, JavaScript, Method, TypedArray, TypedArrays, prototype
The filter() method creates a new typed array with all elements that pass the test implemented by the provided function. This method has the same algorithm as Array.prototype.filter(). TypedArray is one of the typed array types here.
592 TypedArray.prototype.find() ECMAScript6, JavaScript, Method, Reference, TypedArray, TypedArrays, prototype
The find() method returns a value in the typed array, if an element satisfies the provided testing function. Otherwise undefined is returned. TypedArray is one of the typed array types here.
593 TypedArray.prototype.findIndex() ECMAScript6, JavaScript, Method, Reference, TypedArray, TypedArrays, prototype
The findIndex() method returns an index in the typed array, if an element in the typed array satisfies the provided testing function. Otherwise -1 is returned.
594 TypedArray.prototype.forEach() ECMAScript6, JavaScript, Method, Reference, TypedArray, TypedArrays, prototype
The forEach() method executes a provided function once per array element. This method has the same algorithm as Array.prototype.forEach(). TypedArray is one of the typed array types here.
595 TypedArray.prototype.includes() ECMAScript7, Experimental, JavaScript, Method, TypedArray, TypedArrays, prototype
The includes() method determines whether a typed array includes a certain element, returning true or false as appropriate. This method has the same algorithm as Array.prototype.includes(). TypedArray is one of the typed array types here.
596 TypedArray.prototype.indexOf() ECMAScript6, JavaScript, Method, TypedArray, TypedArrays, prototype
The indexOf() method returns the first index at which a given element can be found in the typed array, or -1 if it is not present. This method has the same algorithm as Array.prototype.indexOf(). TypedArray is one of the typed array types here.
597 TypedArray.prototype.join() ECMAScript6, JavaScript, Method, TypedArray, TypedArrays, prototype
The join() method joins all elements of an array into a string. This method has the same algorithm as Array.prototype.join(). TypedArray is one of the typed array types here.
598 TypedArray.prototype.keys() ECMAScript6, Iterator, JavaScript, Method, Reference, TypedArray, TypedArrays, prototype
The keys() method returns a new Array Iterator object that contains the keys for each index in the array.
599 TypedArray.prototype.lastIndexOf() ECMAScript6, JavaScript, Method, TypedArray, TypedArrays, prototype
The lastIndexOf() method returns the last index at which a given element can be found in the typed array, or -1 if it is not present. The typed array is searched backwards, starting at fromIndex. This method has the same algorithm as Array.prototype.lastIndexOf(). TypedArray is one of the typed array types here.
600 TypedArray.prototype.length JavaScript, Property, TypedArray, TypedArrays, prototype
The length accessor property represents the length (in elements) of a typed array.
601 TypedArray.prototype.map() ECMAScript6, JavaScript, Method, TypedArray, TypedArrays, prototype
The map() method creates a new typed array with the results of calling a provided function on every element in this typed array. This method has the same algorithm as Array.prototype.map(). TypedArray is one of the typed array types here.
602 TypedArray.prototype.move() JavaScript, Method, Obsolete, TypedArray, prototype
The move() method used to copy the sequence of array elements within the array to the position starting at target. However, this non-standard method has been replaced with the standard TypedArray.prototype.copyWithin() method. TypedArray is one of the typed array types here.
603 TypedArray.prototype.reduce() JavaScript, Method, Reference, TypedArray, TypedArrays, prototype
The reduce() method applies a function against an accumulator and each value of the typed array (from left-to-right) has to reduce it to a single value. This method has the same algorithm as Array.prototype.reduce(). TypedArray is one of the typed array types here.
604 TypedArray.prototype.reduceRight() JavaScript, Method, Reference, TypedArray, TypedArrays, prototype
The reduceRight() method applies a function against an accumulator and each value of the typed array (from right-to-left) has to reduce it to a single value. This method has the same algorithm as Array.prototype.reduceRight(). TypedArray is one of the typed array types here.
605 TypedArray.prototype.reverse() ECMAScript6, JavaScript, Method, TypedArray, TypedArrays, prototype
The reverse() method reverses a typed array in place. The first typed array element becomes the last and the last becomes the first. This method has the same algorithm as Array.prototype.reverse(). TypedArray is one of the typed array types here.
606 TypedArray.prototype.set() JavaScript, Method, TypedArray, TypedArrays, prototype
The set() method stores multiple values in the typed array, reading input values from a specified array.
607 TypedArray.prototype.slice() ECMAScript6, JavaScript, Method, TypedArray, TypedArrays, prototype
The slice() method returns a shallow copy of a portion of a typed array into a new typed array object. This method has the same algorithm as Array.prototype.slice(). TypedArray is one of the typed array types here.
608 TypedArray.prototype.some() ECMAScript6, JavaScript, Method, TypedArray, TypedArrays, prototype
The some() method tests whether some element in the typed array passes the test implemented by the provided function. This method has the same algorithm as Array.prototype.some(). TypedArray is one of the typed array types here.
609 TypedArray.prototype.subarray() JavaScript, Method, TypedArray, TypedArrays, prototype
The subarray() method returns a new TypedArray on the same ArrayBuffer store and with the same element types as for this TypedArray object. The begin offset is inclusive and the end offset is exclusive. TypedArray is one of the typed array types.
610 TypedArray.prototype.values() ECMAScript6, Iterator, JavaScript, Method, TypedArray, TypedArrays, prototype
The values() method returns a new Array Iterator object that contains the values for each index in the array.
611 TypedArray.prototype[@@iterator]() Iterator, JavaScript, Method, Reference, TypedArray, TypedArrays, prototype
The initial value of the @@iterator property is the same function object as the initial value of the values property.
612 URIError Error, JavaScript, Object, Reference, URIError
The URIError object represents an error when a global URI handling function was used in a wrong way.
613 URIError.prototype Error, JavaScript, Property, URIError, prototype
The URIError.prototype property represents the prototype for the URIError constructor.
614 Uint16Array Constructor, JavaScript, TypedArray, TypedArrays, Uint16Array
The Uint16Array typed array represents an array of 16-bit unsigned integers in the platform byte order. If control over byte order is needed, use DataView instead. The contents are initialized to 0. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).
615 Uint32Array Constructor, JavaScript, TypedArray, TypedArrays
The Uint32Array typed array represents an array of 32-bit unsigned integers in the platform byte order. If control over byte order is needed, use DataView instead. The contents are initialized to 0. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).
616 Uint8Array Constructor, JavaScript, TypedArray, TypedArrays, Uint8Array
The Uint8Array typed array represents an array of 8-bit unsigned integers. The contents are initialized to 0. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).
617 Uint8ClampedArray Constructor, JavaScript, TypedArray, TypedArrays, Uint8ClampedArray
The Uint8ClampedArray typed array represents an array of 8-bit unsigned integers clamped to 0-255. The contents are initialized to 0. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).
618 WeakMap ECMAScript6, Experimental, JavaScript, WeakMap
The WeakMap object is a collection of key/value pairs in which the keys are objects and the values can be arbitrary values.
619 WeakMap.prototype ECMAScript6, Experimental, JavaScript, Property, WeakMap
The WeakMap.prototype property represents the prototype for the WeakMap constructor.
620 WeakMap.prototype.clear() JavaScript, Method, Obsolete, WeakMap, prototype
The clear() method removes all elements from a WeakMap object.
621 WeakMap.prototype.delete() ECMAScript6, Experimental, JavaScript, Method, WeakMap, prototype
The delete() method removes the specified element from a WeakMap object.
622 WeakMap.prototype.get() ECMAScript6, Experimental, JavaScript, Method, WeakMap, prototype
The get() method returns a specified element from a WeakMap object.
623 WeakMap.prototype.has() ECMAScript6, Experimental, JavaScript, Method, WeakMap, prototype
The has() method returns a boolean indicating whether an element with the specified key exists in the WeakMap object or not.
624 WeakMap.prototype.set() ECMAScript6, Experimental, JavaScript, Method, WeakMap, prototype
The set() method adds a new element with a specified key and value to a WeakMap object.
625 WeakSet ECMAScript6, Experimental, JavaScript, WeakSet
The WeakSet object lets you store weakly held objects in a collection.
626 WeakSet.prototype ECMAScript6, Experimental, Expérimental, JavaScript, Property, WeakSet
The WeakSet.prototype property represents the prototype for the WeakSet constructor.
627 WeakSet.prototype.add() ECMAScript6, Experimental, JavaScript, Method, WeakSet, prototype
The add() method appends a new object to the end of a WeakSet object.
628 WeakSet.prototype.clear() JavaScript, Method, Obsolete, WeakSet, prototype
The clear() method removes all elements from a WeakSet object.
629 WeakSet.prototype.delete() ECMAScript6, Experimental, JavaScript, Method, WeakSet, prototype
The delete() method removes the specified element from a WeakSet object.
630 WeakSet.prototype.has() ECMAScript6, Experimental, JavaScript, Method, WeakSet, prototype
The has() method returns a boolean indicating whether an object exists in a WeakSet or not.
631 decodeURI() JavaScript
The decodeURI() function decodes a Uniform Resource Identifier (URI) previously created by encodeURI or by a similar routine.
632 decodeURIComponent() JavaScript
The decodeURIComponent() method decodes a Uniform Resource Identifier (URI) component previously created by encodeURIComponent or by a similar routine.
633 encodeURI() JavaScript, URI
The encodeURI() method encodes a Uniform Resource Identifier (URI) by replacing each instance of certain characters by one, two, three, or four escape sequences representing the UTF-8 encoding of the character (will only be four escape sequences for characters composed of two "surrogate" characters).
634 encodeURIComponent() JavaScript, URI
The encodeURIComponent() method encodes a Uniform Resource Identifier (URI) component by replacing each instance of certain characters by one, two, three, or four escape sequences representing the UTF-8 encoding of the character (will only be four escape sequences for characters composed of two "surrogate" characters).
635 escape() Deprecated, JavaScript, deprecated
The deprecated escape() method computes a new string in which certain characters have been replaced by a hexadecimal escape sequence. Use encodeURI or encodeURIComponent instead.
636 eval() JavaScript
The eval() method evaluates JavaScript code represented as a string.
637 isFinite() JavaScript
The global isFinite() function determines whether the passed value is a finite number. If needed, the parameter is first converted to a number.
638 isNaN() JavaScript
The isNaN() function determines whether a value is NaN or not. Note: coercion inside the isNaN function has interesting rules; you may alternatively want to use Number.isNaN(), as defined in ECMAScript 6, or you can use typeof to determine if the value is Not-A-Number.
639 null JavaScript, Literal, Primitive
The value null is a JavaScript literal representing null or an "empty" value, i.e. no object value is present. It is one of JavaScript's primitive values.
640 parseFloat() JavaScript
The parseFloat() function parses a string argument and returns a floating point number.
641 parseInt() JavaScript
The parseInt() function parses a string argument and returns an integer of the specified radix (the base in mathematical numeral systems).
642 undefined JavaScript
The global undefined property represents the primitive value undefined. It is one of JavaScript's primitive types.
643 unescape() JavaScript
The deprecated unescape() method computes a new string in which hexadecimal escape sequences are replaced with the character that it represents. The escape sequences might be introduced by a function like escape. Because unescape is deprecated, use decodeURI or decodeURIComponent instead.
644 uneval() JavaScript, Non-standard
The uneval() method creates an string representation of the source code of an Object.
645 Statements and declarations JavaScript, Reference, Référence, statements
JavaScript applications consist of statements with an appropriate syntax. A single statement may span multiple lines. Multiple statements may occur on a single line if each statement is separated by a semicolon. This isn't a keyword, but a group of keywords.
646 Legacy generator function JavaScript, Legacy Iterator, Non-standard, Reference, Réference, Référence
The legacy generator function statement declares legacy generator functions with the specified parameters.
647 block JavaScript, Reference, Référence, Statement
A block statement (or compound statement in other languages) is used to group zero or more statements. The block is delimited by a pair of curly brackets.
648 break JavaScript, Statement
The break statement terminates the current loop, switch, or label statement and transfers program control to the statement following the terminated statement.
649 class Classes, Declaration, ECMAScript6, Experimental, JavaScript, Statement
The class declaration creates a new class with a given name using prototype-based inheritance.
650 const ECMAScript6, Experimental, JavaScript, Statement
The const declaration creates a read-only named constant.
651 continue JavaScript, Statement
The continue statement terminates execution of the statements in the current iteration of the current or labeled loop, and continues execution of the loop with the next iteration.
652 debugger JavaScript, Statement
The debugger statement invokes any available debugging functionality, such as setting a breakpoint. If no debugging functionality is available, this statement has no effect.
653 do...while JavaScript, Statement
The do...while statement creates a loop that executes a specified statement until the test condition evaluates to false. The condition is evaluated after executing the statement, resulting in the specified statement executing at least once.
654 empty JavaScript, Statement
An empty statement is used to provide no statement, although the JavaScript syntax would expect one.
655 export ECMAScript6, JavaScript, NeedsUpdate, Statement
The following content does not reflect the final state of the ECMAScript 6 modules specification. For more accurate documentation, see ECMAScript 6 modules: the final syntax.
656 for JavaScript, Loop, Statement, for, loop
The for statement creates a loop that consists of three optional expressions, enclosed in parentheses and separated by semicolons, followed by a statement or a set of statements executed in the loop.
657 for each...in Deprecated, E4X, JavaScript, Statement, deprecated
The for each...in statement iterates a specified variable over all values of object's properties. For each distinct property, a specified statement is executed.
658 for...in JavaScript, Statement
The for..in statement iterates over the enumerable properties of an object, in arbitrary order. For each distinct property, statements can be executed.
659 for...of ECMAScript6, Experimental, JavaScript, Statement
The for...of statement creates a loop Iterating over iterable objects (including ArrayMap, Setarguments object and so on), invoking a custom iteration hook with statements to be executed for the value of each distinct property.
660 function JavaScript, Statement
The function declaration defines a function with the specified parameters.
661 function* ECMAScript6, Experimental, Function, Iterator, JavaScript, Statement
The function* declaration (function keyword followed by an asterisk) defines a generator function, which returns a Generator object.
662 if...else JavaScript, Statement
The if statement executes a statement if a specified condition is true. If the condition is false, another statement can be executed.
663 import ECMAScript6, Experimental, JavaScript, Modules, Statement
The following content does not reflect the final state of the ECMAScript 6 modules specification. For more accurate documentation, see ECMAScript 6 modules: the final syntax.
664 label JavaScript, Statement
The labeled statement can be used with break or continue statements. It is prefixing a statement with an identifier which you can refer to.
665 let ECMAScript6, Experimental, JavaScript, Statement
The let statement declares a block scope local variable, optionally initializing it to a value.
666 return JavaScript, Statement
The return statement ends function execution and specifies a value to be returned to the function caller.
667 switch JavaScript, Statement
The switch statement evaluates an expression, matching the expression's value to a case clause, and executes statements associated with that case.
668 throw JavaScript, Statement
The throw statement throws a user-defined exception. Execution of the current function will stop (the statements after throw won't be executed), and control will be passed to the first catch block in the call stack. If no catch block exists among caller functions, the program will terminate.
669 try...catch JavaScript, Statement
The try...catch statement marks a block of statements to try, and specifies a response, should an exception be thrown.
670 var JavaScript, Statement
The variable statement declares a variable, optionally initializing it to a value.
671 while JavaScript, Statement
The while statement creates a loop that executes a specified statement as long as the test condition evaluates to true. The condition is evaluated before executing the statement.
672 with Deprecated, JavaScript, Statement, deprecated
The with statement extends the scope chain for a statement.
673 Strict mode ECMAScript5, JavaScript, Strict Mode
ECMAScript 5's strict mode is a way to opt in to a restricted variant of JavaScript. Strict mode isn't just a subset: it intentionally has different semantics from normal code. Browsers not supporting strict mode will run strict mode code with different behavior from browsers that do, so don't rely on strict mode without feature-testing for support for the relevant aspects of strict mode. Strict mode code and non-strict mode code can coexist, so scripts can opt into strict mode incrementally.
674 Transitioning to strict mode Advanced, JavaScript
ECMAScript 5 introduced strict mode which is now implemented in all major browsers (including IE10). While making web browsers interpret code as strict is easy (just add "use strict"; at the top of your source code), transitioning an existing code base to strict mode requires a bit more work.
675 Template strings ECMAScript6, Experimental, JavaScript
Template strings are string literals allowing embedded expressions. You can use multi-line strings and string interpolation features with them.
676 JavaScript shells Extensions, JavaScript, Tools
A JavaScript shell allows you to quickly test snippets of JavaScript code without having to reload a web page. They are extremely useful for developing and debugging code.
677 JavaScript technologies overview Beginner, DOM, JavaScript, beginner
Whereas HTML defines a webpage's structure and content and CSS sets the formatting and appearance, JavaScript adds interactivity to a webpage and creates rich web applications.
678 JavaScript typed arrays Guide, JavaScript, guide
JavaScript typed arrays are array-like objects and provide a mechanism for accessing raw binary data. As you already know, Array objects grow and shrink dynamically and can have any JavaScript value. JavaScript engines perform optimizations so that these arrays are fast. However, as web applications become more and more powerful, adding features such as audio and video manipulation, access to raw data using WebSockets, and so forth, it has become clear that there are times when it would be helpful for JavaScript code to be able to quickly and easily manipulate raw binary data in typed arrays.
679 Memory Management JavaScript, memory
Low-level languages, like C, have low-level memory management primitives like malloc() and free(). On the other hand, JavaScript values are allocated when things (objects, strings, etc.) are created and "automatically" free'd when they are not used anymore. The latter process is called garbage collection. This "automatically" is a source of confusion and gives JavaScript (and high-level languages) developers the impression they can decide not to care about memory management. This is a mistake.
680 New in JavaScript JavaScript, Versions
This chapter contains information about JavaScript's version history and implementation status for Mozilla/SpiderMonkey-based JavaScript applications, such as Firefox.
681 ECMAScript 5 support in Mozilla ECMAScript5, JavaScript, Versions
ECMAScript 5.1, the latest edition of the standard upon which JavaScript is based, was approved in June 2011.
682 ECMAScript 6 support in Mozilla ECMAScript6, Firefox, JavaScript
ECMAScript 2015 (6th Edition) is the current version of the ECMAScript Language Specification standard. Commonly referred to as "ES6", it defines the standard for the JavaScript implementation in SpiderMonkey, the engine used in Firefox and other Mozilla applications.
683 ECMAScript 7 support in Mozilla ECMAScript7, Firefox, JavaScript
ECMAScript 7 is the next evolution of the ECMA-262 standard (commonly referred to as JavaScript). Even before ECMAScript 6 was finalized on June 17, 2015, new features were already being proposed. You can see the latest proposals on the tc39/ecma262 GitHub repository.
684 Firefox JavaScript changelog JavaScript, Versions
The following is a changelog for JavaScript features in Firefox releases.
685 New in JavaScript 1.1 JavaScript, Versions
The following is a changelog for JavaScript from Netscape Navigator 2.0 to 3.0. The old Netscape documentation references this as "Features added after version 1". Netscape Navigator 3.0 was released on August 19, 1996. Netscape Navigator 3.0 was the second major version of the browser with JavaScript support.
686 New in JavaScript 1.2 JavaScript, Versions
The following is a changelog for JavaScript from Netscape Navigator 3.0 to 4.0. The old Netscape documentation can be found on archive.org. Netscape Navigator 4.0 was released on June 11, 1997. Netscape Navigator 4.0 was the third major version of the browser with JavaScript support.
687 New in JavaScript 1.3 JavaScript, Versions
The following is a changelog for JavaScript from Netscape Navigator 4.0 to 4.5. The old Netscape documentation can be found on archive.org. Netscape Navigator 4.5 was released on October 19, 1998.
688 New in JavaScript 1.4 JavaScript, Versions
The following is a changelog for JavaScript 1.4, which was only used for Netscape's server side JavaScript released in 1999. The old Netscape documentation can be found on archive.org.
689 New in JavaScript 1.5 JavaScript, Versions
The following is a changelog for JavaScript 1.5. This version was included in Netscape Navigator 6.0 was released on November 14, 2000 and was also used in later versions of Netscape Navigator and Firefox 1.0. You can compare JavaScript 1.5 to JScript version 5.5 and Internet Explorer 5.5, which was released in July 2000. The corresponding ECMA standard is ECMA-262 Edition 3 (from December 1999).
690 New in JavaScript 1.6 JavaScript, Versions
The following is a changelog for JavaScript 1.6. This version was included in Firefox 1.5 (Gecko 1.8), which was released in November 2005. The corresponding ECMA standard is ECMA-262 Edition 3 and ECMAScript for XML (E4X) with some additional features. Several new features were introduced: E4X, several new Array methods, and Array and String generics.
691 New in JavaScript 1.7 JavaScript, Versions
The following is a changelog for JavaScript 1.7. This version was included in Firefox 2 (October 2006).
692 New in JavaScript 1.8 JavaScript, Versions
The following is a changelog for JavaScript 1.8. This version was included in Firefox 3 and is part of Gecko 1.9. See bug 380236 for a tracking development bug for JavaScript 1.8.
693 New in JavaScript 1.8.1 Firefox 3.5, JavaScript, Versions
The following is a changelog for JavaScript 1.8.1. This version was included in Firefox 3.5.
694 New in JavaScript 1.8.5 ECMAScript5, Firefox 4, JavaScript, JavaScript 1.8.5, Versions
The following is a changelog for JavaScript 1.8.5. This version was included in Firefox 4.
695 SIMD types JavaScript, SIMD
The experimental JavaScript SIMD API introduces vector objects that utilize SIMD/SSE instructions on supporting CPUs; SIMD is short for Single Instruction/Multiple Data. SIMD operations are methods that process multiple data with a single instruction. In contrary, scalar operations (SISD) process only one individual data with a single instruction.

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