Önkénteseink még nem fordították le ezt a cikket magyar nyelvre. Csatlakozzon, és segítsen a munka befejezésében!
Elolvashatja a cikket English (US) nyelven is.

The String global object is a constructor for strings or a sequence of characters.

Syntax

String literals take the forms:

'string text'
"string text"
"中文 español Deutsch English देवनागरी العربية português বাংলা русский 日本語 ਪੰਜਾਬੀ 한국어 தமிழ் עברית"

Strings can also be created using the String global object directly:

String(thing)

Parameters

thing
Anything to be converted to a string.

Template literals

Starting with ECMAScript 2015, string literals can also be so-called Template literals:

`hello world`
`hello!
 world!`
`hello ${who}`
tag `<a>${who}</a>`

Escape notation

Besides regular, printable characters, special characters can be encoded using escape notation:

Code Output
\XXX an octal Latin-1 character.
\' single quote
\" double quote
\\ backslash
\n new line
\r carriage return
\v vertical tab
\t tab
\b backspace
\f form feed
\uXXXX unicode codepoint
\u{X} ... \u{XXXXXX} unicode codepoint
\xXX the Latin-1 character

Unlike some other languages, JavaScript makes no distinction between single-quoted strings and double-quoted strings; therefore, the escape sequences above work in strings created with either single or double quotes.

Long literal strings

Sometimes, your code will include strings which are very long. Rather than having lines that go on endlessly, or wrap at the whim of your editor, you may wish to specifically break the string into multiple lines in the source code without affecting the actual string contents. There are two ways you can do this.

You can use the + operator to append multiple strings together, like this:

let longString = "This is a very long string which needs " +
                 "to wrap across multiple lines because " +
                 "otherwise my code is unreadable.";

Or you can use the backslash character ("\") at the end of each line to indicate that the string will continue on the next line. Make sure there is no space or any other character after the backslash (except for a line break), or as an indent; otherwise it will not work. That form looks like this:

let longString = "This is a very long string which needs \
to wrap across multiple lines because \
otherwise my code is unreadable.";

Both of these result in identical strings being created.

Description

Strings are useful for holding data that can be represented in text form. Some of the most-used operations on strings are to check their length, to build and concatenate them using the + and += string operators, checking for the existence or location of substrings with the indexOf() method, or extracting substrings with the substring() method.

Character access

There are two ways to access an individual character in a string. The first is the charAt() method:

return 'cat'.charAt(1); // returns "a"

The other way (introduced in ECMAScript 5) is to treat the string as an array-like object, where individual characters correspond to a numerical index:

return 'cat'[1]; // returns "a"

For character access using bracket notation, attempting to delete or assign a value to these properties will not succeed. The properties involved are neither writable nor configurable. (See Object.defineProperty() for more information.)

Comparing strings

C developers have the strcmp() function for comparing strings. In JavaScript, you just use the less-than and greater-than operators:

var a = 'a';
var b = 'b';
if (a < b) { // true
  console.log(a + ' is less than ' + b);
} else if (a > b) {
  console.log(a + ' is greater than ' + b);
} else {
  console.log(a + ' and ' + b + ' are equal.');
}

A similar result can be achieved using the localeCompare() method inherited by String instances.

Distinction between string primitives and String objects

Note that JavaScript distinguishes between String objects and primitive string values. (The same is true of Boolean and Numbers.)

String literals (denoted by double or single quotes) and strings returned from String calls in a non-constructor context (i.e., without using the new keyword) are primitive strings. JavaScript automatically converts primitives to String objects, so that it's possible to use String object methods for primitive strings. In contexts where a method is to be invoked on a primitive string or a property lookup occurs, JavaScript will automatically wrap the string primitive and call the method or perform the property lookup.

var s_prim = 'foo';
var s_obj = new String(s_prim);

console.log(typeof s_prim); // Logs "string"
console.log(typeof s_obj);  // Logs "object"

String primitives and String objects also give different results when using eval(). Primitives passed to eval are treated as source code; String objects are treated as all other objects are, by returning the object. For example:

var s1 = '2 + 2';             // creates a string primitive
var s2 = new String('2 + 2'); // creates a String object
console.log(eval(s1));        // returns the number 4
console.log(eval(s2));        // returns the string "2 + 2"

For these reasons, the code may break when it encounters String objects when it expects a primitive string instead, although generally, authors need not worry about the distinction.

A String object can always be converted to its primitive counterpart with the valueOf() method.

console.log(eval(s2.valueOf())); // returns the number 4
Note: For another possible approach to strings in JavaScript, please read the article about StringView — a C-like representation of strings based on typed arrays.

Properties

String.prototype
Allows the addition of properties to a String object.

Methods

String.fromCharCode()
Returns a string created by using the specified sequence of Unicode values.
String.fromCodePoint()
Returns a string created by using the specified sequence of code points.
String.raw()
Returns a string created from a raw template string.

String generic methods

String generics are non-standard, deprecated and will get removed in the near future.

The String instance methods are also available in Firefox as of JavaScript 1.6 (not part of the ECMAScript standard) on the String object for applying String methods to any object:

var num = 15;
console.log(String.replace(num, "5", "2"));

For migrating away from String generics, see also Warning: String.x is deprecated; use String.prototype.x instead.

Generics are also available on Array methods.

String instances

Properties

String.prototype.constructor
Specifies the function that creates an object's prototype.
String.prototype.length
Reflects the length of the string.
N
Used to access the character in the Nth position where N is an integer between 0 and one less than the value of length. These properties are read-only.

Methods

Methods unrelated to HTML

String.prototype.charAt()
Returns the character (exactly one UTF-16 code unit) at the specified index.
String.prototype.charCodeAt()
Returns a number that is the UTF-16 code unit value at the given index.
String.prototype.codePointAt()
Returns a nonnegative integer Number that is the code point value of the UTF-16 encoded code point starting at the specified index.
String.prototype.concat()
Combines the text of two strings and returns a new string.
String.prototype.includes()
Determines whether one string may be found within another string.
String.prototype.endsWith()
Determines whether a string ends with the characters of another string.
String.prototype.indexOf()
Returns the index within the calling String object of the first occurrence of the specified value, or -1 if not found.
String.prototype.lastIndexOf()
Returns the index within the calling String object of the last occurrence of the specified value, or -1 if not found.
String.prototype.localeCompare()
Returns a number indicating whether a reference string comes before or after or is the same as the given string in sort order.
String.prototype.match()
Used to match a regular expression against a string.
String.prototype.normalize()
Returns the Unicode Normalization Form of the calling string value.
String.prototype.padEnd()
Pads the current string from the end with a given string to create a new string from a given length.
String.prototype.padStart()
Pads the current string from the start with a given string to create a new string from a given length.
String.prototype.quote()
Wraps the string in double quotes (""").
String.prototype.repeat()
Returns a string consisting of the elements of the object repeated the given times.
String.prototype.replace()
Used to find a match between a regular expression and a string, and to replace the matched substring with a new substring.
String.prototype.search()
Executes the search for a match between a regular expression and a specified string.
String.prototype.slice()
Extracts a section of a string and returns a new string.
String.prototype.split()
Splits a String object into an array of strings by separating the string into substrings.
String.prototype.startsWith()
Determines whether a string begins with the characters of another string.
String.prototype.substr()
Returns the characters in a string beginning at the specified location through the specified number of characters.
String.prototype.substring()
Returns the characters in a string between two indexes into the string.
String.prototype.toLocaleLowerCase()
The characters within a string are converted to lower case while respecting the current locale. For most languages, this will return the same as toLowerCase().
String.prototype.toLocaleUpperCase()
The characters within a string are converted to upper case while respecting the current locale. For most languages, this will return the same as toUpperCase().
String.prototype.toLowerCase()
Returns the calling string value converted to lower case.
String.prototype.toSource()
Returns an object literal representing the specified object; you can use this value to create a new object. Overrides the Object.prototype.toSource() method.
String.prototype.toString()
Returns a string representing the specified object. Overrides the Object.prototype.toString() method.
String.prototype.toUpperCase()
Returns the calling string value converted to uppercase.
String.prototype.trim()
Trims whitespace from the beginning and end of the string. Part of the ECMAScript 5 standard.
String.prototype.trimStart()
String.prototype.trimLeft()
Trims whitespace from the beginning of the string.
String.prototype.trimEnd()
String.prototype.trimRight()
Trims whitespace from the end of the string.
String.prototype.valueOf()
Returns the primitive value of the specified object. Overrides the Object.prototype.valueOf() method.
String.prototype[@@iterator]()
Returns a new Iterator object that iterates over the code points of a String value, returning each code point as a String value.

HTML wrapper methods

Examples

String conversion

It's possible to use String as a more reliable toString() alternative, as it works when used on null, undefined, and on symbols. For example:

var outputStrings = [];
for (var i = 0, n = inputValues.length; i < n; ++i) {
  outputStrings.push(String(inputValues[i]));
}

Specifications

Specification Status Comment
ECMAScript 1st Edition (ECMA-262) Standard Initial definition.
ECMAScript 5.1 (ECMA-262)
The definition of 'String' in that specification.
Standard  
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'String' in that specification.
Standard  
ECMAScript Latest Draft (ECMA-262)
The definition of 'String' in that specification.
Draft  

Browser compatibility

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung InternetNode.js
Basic supportChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
@@iteratorChrome Full support YesEdge Full support YesFirefox Full support 36
Full support 36
No support 27 — 36
Notes Alternate Name
Notes A placeholder property named @@iterator is used.
Alternate Name Uses the non-standard name: @@iterator
No support 17 — 27
Notes Alternate Name
Notes A placeholder property named iterator is used.
Alternate Name Uses the non-standard name: iterator
IE No support NoOpera No support NoSafari No support NoWebView Android No support NoChrome Android No support NoEdge Mobile ? Firefox Android Full support 36
Full support 36
No support 27 — 36
Notes Alternate Name
Notes A placeholder property named @@iterator is used.
Alternate Name Uses the non-standard name: @@iterator
No support 17 — 27
Notes Alternate Name
Notes A placeholder property named iterator is used.
Alternate Name Uses the non-standard name: iterator
Opera Android No support NoSafari iOS No support NoSamsung Internet Android No support Nonodejs Full support 0.12
Unicode code point escapes \u{xxxxxx}Chrome Full support YesEdge ? Firefox Full support 40IE ? Opera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile ? Firefox Android Full support 40Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
anchor
Deprecated
Chrome Full support YesEdge Full support YesFirefox Full support 1
Notes
Full support 1
Notes
Notes Starting with version 17, the quotation mark (") is replaced by its HTML reference character (") in strings supplied for the name parameter.
IE No support NoOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
big
Deprecated
Chrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
blink
Deprecated
Chrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
bold
Deprecated
Chrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
charAtChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
charCodeAtChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
codePointAtChrome Full support 41Edge Full support YesFirefox Full support 29IE No support NoOpera Full support 28Safari Full support 10WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 29Opera Android Full support YesSafari iOS Full support 10Samsung Internet Android Full support Yesnodejs Full support 4.0.0
Full support 4.0.0
Full support 0.12
Disabled
Disabled From version 0.12: this feature is behind the --harmony runtime flag.
concatChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
endsWithChrome Full support 41Edge Full support YesFirefox Full support 17IE No support NoOpera Full support 28Safari Full support 9WebView Android Full support YesChrome Android Full support 36Edge Mobile Full support YesFirefox Android Full support 17Opera Android Full support YesSafari iOS Full support 9Samsung Internet Android Full support Yesnodejs Full support 4.0.0
Full support 4.0.0
Full support 0.12
Disabled
Disabled From version 0.12: this feature is behind the --harmony runtime flag.
fixed
Deprecated
Chrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
fontcolor
Deprecated
Chrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
fontsize
Deprecated
Chrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
fromCharCodeChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
fromCodePointChrome Full support 41Edge Full support YesFirefox Full support 29IE No support NoOpera Full support 28Safari Full support 10WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 29Opera Android Full support YesSafari iOS Full support 10Samsung Internet Android Full support Yesnodejs Full support 4.0.0
Full support 4.0.0
Full support 0.12
Disabled
Disabled From version 0.12: this feature is behind the --harmony runtime flag.
includesChrome Full support 41Edge Full support YesFirefox Full support 40
Full support 40
No support 18 — 48
Alternate Name
Alternate Name Uses the non-standard name: contains
IE No support NoOpera Full support YesSafari Full support 9WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 40
Full support 40
No support 18 — 48
Alternate Name
Alternate Name Uses the non-standard name: contains
Opera Android Full support YesSafari iOS Full support 9Samsung Internet Android Full support Yesnodejs Full support 4.0.0
indexOfChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
italics
Deprecated
Chrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
lastIndexOfChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support 6Opera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
lengthChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
link
Deprecated
Chrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
localeCompareChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
localeCompare.localesChrome Full support 24Edge Full support YesFirefox Full support 29IE Full support 11Opera Full support 15Safari Full support 10WebView Android No support NoChrome Android Full support 26Edge Mobile ? Firefox Android No support NoOpera Android No support NoSafari iOS Full support 10Samsung Internet Android Full support Yesnodejs ?
localeCompare.optionsChrome Full support 24Edge Full support YesFirefox Full support 29IE Full support 11Opera Full support 15Safari Full support 10WebView Android No support NoChrome Android Full support 26Edge Mobile ? Firefox Android No support NoOpera Android No support NoSafari iOS Full support 10Samsung Internet Android Full support Yesnodejs ?
matchChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
match.flags
DeprecatedNon-standard
Chrome No support NoEdge No support NoFirefox No support 1 — 49IE No support NoOpera No support NoSafari No support NoWebView Android No support NoChrome Android No support NoEdge Mobile No support NoFirefox Android No support 4 — 49Opera Android No support NoSafari iOS No support NoSamsung Internet Android No support Nonodejs No support No
normalizeChrome Full support 34Edge Full support YesFirefox Full support 31IE No support NoOpera Full support YesSafari Full support 10WebView Android No support NoChrome Android Full support 34Edge Mobile Full support YesFirefox Android Full support 31Opera Android Full support YesSafari iOS Full support 10Samsung Internet Android Full support Yesnodejs Full support 0.12
padEndChrome Full support 57Edge Full support 15Firefox Full support 48IE No support NoOpera Full support 44Safari Full support 10WebView Android Full support 57Chrome Android Full support 57Edge Mobile Full support YesFirefox Android Full support 48Opera Android Full support 44Safari iOS Full support 10Samsung Internet Android Full support 7.0nodejs Full support 8.0.0
Full support 8.0.0
Full support 7.0.0
Disabled
Disabled From version 7.0.0: this feature is behind the --harmony runtime flag.
padStartChrome Full support 57Edge Full support 15Firefox Full support 48IE No support NoOpera Full support 44Safari Full support 10WebView Android Full support 57Chrome Android Full support 57Edge Mobile Full support YesFirefox Android Full support 48Opera Android Full support 44Safari iOS Full support 10Samsung Internet Android Full support 7.0nodejs Full support 8.0.0
Full support 8.0.0
Full support 7.0.0
Disabled
Disabled From version 7.0.0: this feature is behind the --harmony runtime flag.
prototypeChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
quote
Deprecated
Chrome No support NoEdge No support NoFirefox No support 1 — 37IE No support NoOpera No support NoSafari No support NoWebView Android No support NoChrome Android No support NoEdge Mobile No support NoFirefox Android No support 4 — 37Opera Android No support NoSafari iOS No support NoSamsung Internet Android No support Nonodejs No support No
rawChrome Full support 41Edge Full support YesFirefox Full support 34IE No support NoOpera No support NoSafari Full support 10WebView Android No support NoChrome Android Full support 41Edge Mobile Full support YesFirefox Android Full support 34Opera Android No support NoSafari iOS Full support 10Samsung Internet Android Full support 4.0nodejs Full support 4.0.0
repeatChrome Full support 41Edge Full support YesFirefox Full support 24IE No support NoOpera Full support YesSafari Full support 9WebView Android No support NoChrome Android Full support 36Edge Mobile Full support YesFirefox Android Full support 24Opera Android Full support YesSafari iOS Full support 9Samsung Internet Android Full support Yesnodejs Full support 4.0.0
Full support 4.0.0
Full support 0.12
Disabled
Disabled From version 0.12: this feature is behind the --harmony runtime flag.
replaceChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
replace.flags
DeprecatedNon-standard
Chrome No support NoEdge No support NoFirefox No support 1 — 49IE No support NoOpera No support NoSafari No support NoWebView Android No support NoChrome Android No support NoEdge Mobile No support NoFirefox Android No support 4 — 49Opera Android No support NoSafari iOS No support NoSamsung Internet Android No support Nonodejs No support No
searchChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
search.flags
DeprecatedNon-standard
Chrome No support NoEdge No support NoFirefox No support 1 — 49IE No support NoOpera No support NoSafari No support NoWebView Android No support NoChrome Android No support NoEdge Mobile No support NoFirefox Android No support 4 — 49Opera Android No support NoSafari iOS No support NoSamsung Internet Android No support Nonodejs No support No
sliceChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
small
Deprecated
Chrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
splitChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
startsWithChrome Full support 41Edge Full support YesFirefox Full support 17IE No support NoOpera Full support 28Safari Full support 9WebView Android Full support YesChrome Android Full support 36Edge Mobile Full support YesFirefox Android Full support 17Opera Android Full support YesSafari iOS Full support 9Samsung Internet Android Full support Yesnodejs Full support 4.0.0
Full support 4.0.0
Full support 0.12
Disabled
Disabled From version 0.12: this feature is behind the --harmony runtime flag.
strike
Deprecated
Chrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
sub
Deprecated
Chrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
substr
Deprecated
Chrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
substringChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
sup
Deprecated
Chrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
toLocaleLowerCaseChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
toLocaleLowerCase.localeChrome ? Edge ? Firefox Full support 55IE ? Opera ? Safari ? WebView Android ? Chrome Android ? Edge Mobile ? Firefox Android Full support 55Opera Android ? Safari iOS ? Samsung Internet Android ? nodejs ?
toLocaleUpperCaseChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
toLocaleUpperCase.localeChrome ? Edge ? Firefox Full support 55IE ? Opera ? Safari ? WebView Android ? Chrome Android ? Edge Mobile ? Firefox Android Full support 55Opera Android ? Safari iOS ? Samsung Internet Android ? nodejs ?
toLowerCaseChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
toSource
Non-standard
Chrome No support NoEdge No support NoFirefox Full support 1IE No support NoOpera No support NoSafari No support NoWebView Android No support NoChrome Android No support NoEdge Mobile No support NoFirefox Android Full support 4Opera Android No support NoSafari iOS No support NoSamsung Internet Android No support Nonodejs No support No
toStringChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
toUpperCaseChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
trimChrome Full support YesEdge Full support YesFirefox Full support 3.5IE Full support 9Opera Full support 10.5Safari Full support 5WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
trimEndChrome Full support 66
Full support 66
Full support Yes
Alternate Name
Alternate Name Uses the non-standard name: trimRight
Edge ? Firefox Full support 61
Full support 61
Full support 3.5
Alternate Name
Alternate Name Uses the non-standard name: trimRight
IE No support NoOpera Full support 53Safari ? WebView Android Full support 66
Full support 66
Full support Yes
Alternate Name
Alternate Name Uses the non-standard name: trimRight
Chrome Android Full support 66
Full support 66
Full support Yes
Alternate Name
Alternate Name Uses the non-standard name: trimRight
Edge Mobile ? Firefox Android Full support 61
Full support 61
Full support 4
Alternate Name
Alternate Name Uses the non-standard name: trimRight
Opera Android Full support 53Safari iOS ? Samsung Internet Android ? nodejs Full support 10.0.0
trimStartChrome Full support 66
Full support 66
Full support Yes
Alternate Name
Alternate Name Uses the non-standard name: trimLeft
Edge ? Firefox Full support 61
Full support 61
Full support 3.5
Alternate Name
Alternate Name Uses the non-standard name: trimLeft
IE No support NoOpera Full support 53Safari ? WebView Android Full support 66
Full support 66
Full support Yes
Alternate Name
Alternate Name Uses the non-standard name: trimLeft
Chrome Android Full support 66
Full support 66
Full support Yes
Alternate Name
Alternate Name Uses the non-standard name: trimLeft
Edge Mobile ? Firefox Android Full support 61
Full support 61
Full support 4
Alternate Name
Alternate Name Uses the non-standard name: trimLeft
Opera Android Full support 53Safari iOS ? Samsung Internet Android ? nodejs Full support 10.0.0
valueOfChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
Non-standard. Expect poor cross-browser support.
Non-standard. Expect poor cross-browser support.
Deprecated. Not for use in new websites.
Deprecated. Not for use in new websites.
See implementation notes.
See implementation notes.
User must explicitly enable this feature.
User must explicitly enable this feature.
Uses a non-standard name.
Uses a non-standard name.

See also