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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).
Syntax
new Float32Array(); // new in ES2017 new Float32Array(length); new Float32Array(typedArray); new Float32Array(object); new Float32Array(buffer [, byteOffset [, length]]);
For more information about the constructor syntax and the parameters, see TypedArray.
Properties
Float32Array.BYTES_PER_ELEMENT
- Returns a number value of the element size.
4
in the case of anFloat32Array
. - Float32Array.length
- Static length property whose value is 0. For the actual length (number of elements), see
Float32Array.prototype.length
. Float32Array.name
- Returns the string value of the constructor name. In the case of the
Float32Array
type: "Float32Array". Float32Array.prototype
- Prototype for the TypedArray objects.
Methods
Float32Array.from()
- Creates a new
Float32Array
from an array-like or iterable object. See alsoArray.from()
. Float32Array.of()
- Creates a new
Float32Array
with a variable number of arguments. See alsoArray.of()
.
Float32Array
prototype
All Float32Array
objects inherit from %TypedArray%.prototype
.
Properties
Float32Array.prototype.constructor
- Returns the function that created an instance's prototype. This is the
Float32Array
constructor by default. Float32Array.prototype.buffer
Read only- Returns the
ArrayBuffer
referenced by theFloat32Array
Fixed at construction time and thus read only. Float32Array.prototype.byteLength
Read only- Returns the length (in bytes) of the
Float32Array
from the start of itsArrayBuffer
. Fixed at construction time and thus read only. Float32Array.prototype.byteOffset
Read only- Returns the offset (in bytes) of the
Float32Array
from the start of itsArrayBuffer
. Fixed at construction time and thus read only. Float32Array.prototype.length
Read only- Returns the number of elements hold in the
Float32Array
. Fixed at construction time and thus read only.
Methods
Float32Array.prototype.copyWithin()
- Copies a sequence of array elements within the array. See also
Array.prototype.copyWithin()
. Float32Array.prototype.entries()
- Returns a new
Array Iterator
object that contains the key/value pairs for each index in the array. See alsoArray.prototype.entries()
. Float32Array.prototype.every()
- Tests whether all elements in the array pass the test provided by a function. See also
Array.prototype.every()
. Float32Array.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()
. Float32Array.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()
. Float32Array.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()
. Float32Array.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()
. Float32Array.prototype.forEach()
- Calls a function for each element in the array. See also
Array.prototype.forEach()
. Float32Array.prototype.includes()
- Determines whether a typed array includes a certain element, returning
true
orfalse
as appropriate. See alsoArray.prototype.includes()
. Float32Array.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()
. Float32Array.prototype.join()
- Joins all elements of an array into a string. See also
Array.prototype.join()
. Float32Array.prototype.keys()
- Returns a new
Array Iterator
that contains the keys for each index in the array. See alsoArray.prototype.keys()
. Float32Array.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()
. Float32Array.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()
. Float32Array.prototype.move()
Unimplemented- Former non-standard version of
Float32Array.prototype.copyWithin()
. Float32Array.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()
. Float32Array.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()
. Float32Array.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()
. Float32Array.prototype.set()
- Stores multiple values in the typed array, reading input values from a specified array.
Float32Array.prototype.slice()
- Extracts a section of an array and returns a new array. See also
Array.prototype.slice()
. Float32Array.prototype.some()
- Returns true if at least one element in this array satisfies the provided testing function. See also
Array.prototype.some()
. Float32Array.prototype.sort()
- Sorts the elements of an array in place and returns the array. See also
Array.prototype.sort()
. Float32Array.prototype.subarray()
- Returns a new
Float32Array
from the given start and end element index. Float32Array.prototype.values()
- Returns a new
Array Iterator
object that contains the values for each index in the array. See alsoArray.prototype.values()
. Float32Array.prototype.toLocaleString()
- Returns a localized string representing the array and its elements. See also
Array.prototype.toLocaleString()
. Float32Array.prototype.toString()
- Returns a string representing the array and its elements. See also
Array.prototype.toString()
. Float32Array.prototype[@@iterator]()
- Returns a new
Array Iterator
object that contains the values for each index in the array.
Examples
Different ways to create a Float32Array
:
// From a length var float32 = new Float32Array(2); float32[0] = 42; console.log(float32[0]); // 42 console.log(float32.length); // 2 console.log(float32.BYTES_PER_ELEMENT); // 4 // From an array var arr = new Float32Array([21,31]); console.log(arr[1]); // 31 // From another TypedArray var x = new Float32Array([21, 31]); var y = new Float32Array(x); console.log(y[0]); // 21 // From an ArrayBuffer var buffer = new ArrayBuffer(16); var z = new Float32Array(buffer, 0, 4); // From an iterable var iterable = function*(){ yield* [1,2,3]; }(); var float32 = new Float32Array(iterable); // Float32Array[1, 2, 3]
Specifications
Specification | Status | Comment |
---|---|---|
Typed Array Specification | Obsolete | Superseded by ECMAScript 2015. |
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'TypedArray constructors' in that specification. |
Standard | Initial definition in an ECMA standard. Specified that new is required. |
ECMAScript Latest Draft (ECMA-262) The definition of 'TypedArray constructors' in that specification. |
Draft | ECMAScript 2017 changed the Float32Array constructor to use the ToIndex operation and allows constructors with no arguments. |
Browser compatibility
Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | 7 | Yes | 4 | 10 | 11.6 | 5.1 |
Float32Array() without new throws | Yes | Yes | 44 | No | Yes | ? |
Iterable in constructor | ? | ? | 52 | ? | ? | ? |
Constructor without arguments | ? | ? | 55 | ? | ? | ? |
Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | Opera Android | iOS Safari | Samsung Internet |
---|---|---|---|---|---|---|---|
Basic support | 4 | Yes | Yes | 4 | 11.6 | 4.2 | Yes |
Float32Array() without new throws | ? | ? | ? | 44 | ? | ? | ? |
Iterable in constructor | ? | ? | ? | 52 | ? | ? | ? |
Constructor without arguments | ? | ? | ? | 55 | ? | ? | ? |
Compatibility notes
Starting with ECMAScript 2015, Float32Array
constructors require to be constructed with a new
operator. Calling a Float32Array
constructor as a function without new
, will throw a TypeError
from now on.
var dv = Float32Array([1, 2, 3]); // TypeError: calling a builtin Float32Array constructor // without new is forbidden
var dv = new Float32Array([1, 2, 3]);