Float64Array

Объект Float64Array представляет типизированный массив 64-битных чисел с плавающей запятой (соответствует типу double в языке C) с платформо-зависимым порядком байт.Если необходим контроль за порядком байт, то вместо этого объекта используйте DataView. Содержимое инициализируется значением 0. Создав экземпляр Float64Array , можно получить доступ к элементам массива, используя методы объекта или стандартный синтаксис доступа к элементу массива по его индексу (с помощью скобочной нотации - квадратные скобки).

Syntax

new Float64Array(); // new in ES2017
new Float64Array(length);
new Float64Array(typedArray);
new Float64Array(object);
new Float64Array(buffer [, byteOffset [, length]]);

For more information about the constructor syntax and the parameters, see TypedArray.

Properties

Float64Array.BYTES_PER_ELEMENT

Returns a number value of the element size. 8 in the case of an Float64Array.

Float64Array.length

Static length property whose value is 0. For the actual length (number of elements), see Float64Array.prototype.length (en-US).

Float64Array.name (en-US)

Returns the string value of the constructor name. In the case of the Float64Array type: "Float64Array".

Float64Array.prototype (en-US)

Prototype for the TypedArray objects.

Methods

Float64Array.from() (en-US)

Creates a new Float64Array from an array-like or iterable object. See also Array.from().

Float64Array.of() (en-US)

Creates a new Float64Array with a variable number of arguments. See also Array.of().

Float64Array prototype

All Float64Array objects inherit from %TypedArray%.prototype (en-US).

Properties

Float64Array.prototype.constructor

Returns the function that created an instance's prototype. This is the Float64Array constructor by default.

Float64Array.prototype.buffer (en-US) Только для чтения

Returns the ArrayBuffer referenced by the Float64Array Fixed at construction time and thus read only.

Float64Array.prototype.byteLength (en-US) Только для чтения

Returns the length (in bytes) of the Float64Array from the start of its ArrayBuffer. Fixed at construction time and thus read only.

Float64Array.prototype.byteOffset (en-US) Только для чтения

Returns the offset (in bytes) of the Float64Array from the start of its ArrayBuffer. Fixed at construction time and thus read only.

Float64Array.prototype.length (en-US) Только для чтения

Returns the number of elements hold in the Float64Array. Fixed at construction time and thus read only.

Methods

Float64Array.prototype.copyWithin() (en-US)

Copies a sequence of array elements within the array. See also Array.prototype.copyWithin().

Float64Array.prototype.entries() (en-US)

Returns a new Array Iterator object that contains the key/value pairs for each index in the array. See also Array.prototype.entries().

Float64Array.prototype.every() (en-US)

Tests whether all elements in the array pass the test provided by a function. See also Array.prototype.every().

Float64Array.prototype.fill() (en-US)

Fills all the elements of an array from a start index to an end index with a static value. See also Array.prototype.fill().

Float64Array.prototype.filter() (en-US)

Creates a new array with all of the elements of this array for which the provided filtering function returns true. See also Array.prototype.filter().

Float64Array.prototype.find() (en-US)

Returns the found value in the array, if an element in the array satisfies the provided testing function or undefined if not found. See also Array.prototype.find().

Float64Array.prototype.findIndex() (en-US)

Returns the found index in the array, if an element in the array satisfies the provided testing function or -1 if not found. See also Array.prototype.findIndex().

Float64Array.prototype.forEach() (en-US)

Calls a function for each element in the array. See also Array.prototype.forEach().

Float64Array.prototype.includes() (en-US) Экспериментальная возможность

Determines whether a typed array includes a certain element, returning true or false as appropriate. See also Array.prototype.includes().

Float64Array.prototype.indexOf() (en-US)

Returns the first (least) index of an element within the array equal to the specified value, or -1 if none is found. See also Array.prototype.indexOf().

Float64Array.prototype.join()

Joins all elements of an array into a string. See also Array.prototype.join().

Float64Array.prototype.keys() (en-US)

Returns a new Array Iterator that contains the keys for each index in the array. See also Array.prototype.keys().

Float64Array.prototype.lastIndexOf() (en-US)

Returns the last (greatest) index of an element within the array equal to the specified value, or -1 if none is found. See also Array.prototype.lastIndexOf().

Float64Array.prototype.map() (en-US)

Creates a new array with the results of calling a provided function on every element in this array. See also Array.prototype.map().

Float64Array.prototype.reduce() (en-US)

Apply a function against an accumulator and each value of the array (from left-to-right) as to reduce it to a single value. See also Array.prototype.reduce().

Float64Array.prototype.reduceRight() (en-US)

Apply a function against an accumulator and each value of the array (from right-to-left) as to reduce it to a single value. See also Array.prototype.reduceRight().

Float64Array.prototype.reverse() (en-US)

Reverses the order of the elements of an array — the first becomes the last, and the last becomes the first. See also Array.prototype.reverse().

Float64Array.prototype.set()

Stores multiple values in the typed array, reading input values from a specified array.

Float64Array.prototype.slice() (en-US)

Extracts a section of an array and returns a new array. See also Array.prototype.slice().

Float64Array.prototype.some() (en-US)

Returns true if at least one element in this array satisfies the provided testing function. See also Array.prototype.some().

Float64Array.prototype.sort() (en-US)

Sorts the elements of an array in place and returns the array. See also Array.prototype.sort().

Float64Array.prototype.subarray() (en-US)

Returns a new Float64Array from the given start and end element index.

Float64Array.prototype.values() (en-US)

Returns a new Array Iterator object that contains the values for each index in the array. See also Array.prototype.values().

Float64Array.prototype.toLocaleString() (en-US)

Returns a localized string representing the array and its elements. See also Array.prototype.toLocaleString().

Float64Array.prototype.toString() (en-US)

Returns a string representing the array and its elements. See also Array.prototype.toString().

Float64Array.prototype[@@iterator]() (en-US)

Returns a new Array Iterator object that contains the values for each index in the array.

Examples

Different ways to create a Float64Array:

js
// From a length
var float64 = new Float64Array(2);
float64[0] = 42;
console.log(float64[0]); // 42
console.log(float64.length); // 2
console.log(float64.BYTES_PER_ELEMENT); // 8

// From an array
var arr = new Float64Array([21, 31]);
console.log(arr[1]); // 31

// From another TypedArray
var x = new Float64Array([21, 31]);
var y = new Float64Array(x);
console.log(y[0]); // 21

// From an ArrayBuffer
var buffer = new ArrayBuffer(32);
var z = new Float64Array(buffer, 0, 4);

// From an iterable
var iterable = (function* () {
  yield* [1, 2, 3];
})();
var float64 = new Float64Array(iterable);
// Float64Array[1, 2, 3]

Specifications

Specification
ECMAScript Language Specification
# table-49

Совместимость с браузерами

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Compatibility notes

Starting with ECMAScript 2015, Float64Array constructors require to be constructed with a new operator. Calling a Float64Array constructor as a function without new, will throw a TypeError from now on.

js
var dv = Float64Array([1, 2, 3]);
// TypeError: calling a builtin Float64Array constructor
// without new is forbidden
js
var dv = new Float64Array([1, 2, 3]);

See also