Float64Array
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
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 anFloat64Array
. - Float64Array.length
-
Static length property whose value is 0. For the actual length (number of elements), see
Float64Array.prototype.length
. Float64Array.name
-
Returns the string value of the constructor name. In the case of the
Float64Array
type: "Float64Array". Float64Array.prototype
-
Prototype for the TypedArray objects.
Methods
Float64Array.from()
-
Creates a new
Float64Array
from an array-like or iterable object. See alsoArray.from()
. Float64Array.of()
-
Creates a new
Float64Array
with a variable number of arguments. See alsoArray.of()
.
Float64Array
prototype
All Float64Array
objects inherit from %TypedArray%.prototype
.
Properties
Float64Array.prototype.constructor
-
Returns the function that created an instance's prototype. This is the
Float64Array
constructor by default. Float64Array.prototype.buffer
Только для чтения-
Returns the
ArrayBuffer
referenced by theFloat64Array
Fixed at construction time and thus read only. Float64Array.prototype.byteLength
Только для чтения-
Returns the length (in bytes) of the
Float64Array
from the start of itsArrayBuffer
. Fixed at construction time and thus read only. Float64Array.prototype.byteOffset
Только для чтения-
Returns the offset (in bytes) of the
Float64Array
from the start of itsArrayBuffer
. Fixed at construction time and thus read only. Float64Array.prototype.length
Только для чтения-
Returns the number of elements hold in the
Float64Array
. Fixed at construction time and thus read only.
Methods
Float64Array.prototype.copyWithin()
-
Copies a sequence of array elements within the array. See also
Array.prototype.copyWithin()
. Float64Array.prototype.entries()
-
Returns a new
Array Iterator
object that contains the key/value pairs for each index in the array. See alsoArray.prototype.entries()
. Float64Array.prototype.every()
-
Tests whether all elements in the array pass the test provided by a function. See also
Array.prototype.every()
. Float64Array.prototype.fill()
-
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()
-
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()
-
Returns the found value in the array, if an element in the array satisfies the provided testing function or
undefined
if not found. See alsoArray.prototype.find()
. Float64Array.prototype.findIndex()
-
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()
-
Calls a function for each element in the array. See also
Array.prototype.forEach()
. Float64Array.prototype.includes()
Экспериментальная возможность-
Determines whether a typed array includes a certain element, returning
true
orfalse
as appropriate. See alsoArray.prototype.includes()
. Float64Array.prototype.indexOf()
-
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()
-
Returns a new
Array Iterator
that contains the keys for each index in the array. See alsoArray.prototype.keys()
. Float64Array.prototype.lastIndexOf()
-
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()
-
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()
-
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()
-
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()
-
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()
-
Extracts a section of an array and returns a new array. See also
Array.prototype.slice()
. Float64Array.prototype.some()
-
Returns true if at least one element in this array satisfies the provided testing function. See also
Array.prototype.some()
. Float64Array.prototype.sort()
-
Sorts the elements of an array in place and returns the array. See also
Array.prototype.sort()
. Float64Array.prototype.subarray()
-
Returns a new
Float64Array
from the given start and end element index. Float64Array.prototype.values()
-
Returns a new
Array Iterator
object that contains the values for each index in the array. See alsoArray.prototype.values()
. Float64Array.prototype.toLocaleString()
-
Returns a localized string representing the array and its elements. See also
Array.prototype.toLocaleString()
. Float64Array.prototype.toString()
-
Returns a string representing the array and its elements. See also
Array.prototype.toString()
. Float64Array.prototype[@@iterator]()
-
Returns a new
Array Iterator
object that contains the values for each index in the array.
Examples
Different ways to create a Float64Array
:
// 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]
Спецификации
Specification |
---|
ECMAScript Language Specification # table-49 |
Совместимость с браузерами
BCD tables only load in the browser
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.
var dv = Float64Array([1, 2, 3]);
// TypeError: calling a builtin Float64Array constructor
// without new is forbidden
var dv = new Float64Array([1, 2, 3]);