The Float32Array()
typed array constructor creates a new Float32Array
object, which is, 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).
Float32Array() constructor
Syntax
new Float32Array(); // new in ES2017 new Float32Array(length); new Float32Array(typedArray); new Float32Array(object); new Float32Array(buffer); new Float32Array(buffer, byteOffset); new Float32Array(buffer, byteOffset, length);
Parameters
-
length
-
When called with a
length
argument, an internal array buffer is created in memory, of sizelength
multiplied byBYTES_PER_ELEMENT
bytes, containing zeros. -
typedArray
-
When called with a
typedArray
argument, which can be an object of any of the non-bigint typed-array types (such asInt32Array
), thetypedArray
gets copied into a new typed array. Each value intypedArray
is converted to the corresponding type of the constructor before being copied into the new array. The length of the new typed array will be same as the length of thetypedArray
argument. -
object
-
When called with an
object
argument, a new typed array is created as if by theTypedArray.from()
method. -
buffer
,byteOffset
,length
-
When called with a
buffer
, and optionally abyteOffset
and alength
argument, a new typed array view is created that views the specifiedArrayBuffer
. ThebyteOffset
andlength
parameters specify the memory range that will be exposed by the typed array view. If both are omitted, all ofbuffer
is viewed; if onlylength
is omitted, the remainder ofbuffer
is viewed.
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
Browser compatibility
Desktop | Mobile | Server | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | Deno | Node.js | |
Float32Array |
7
|
12
|
4
|
10
|
11.6
|
5.1
|
4
|
18
|
4
|
12
|
4.2
|
1.0
|
1.0
|
0.10.0
|
constructor_without_parameters |
7
|
12
|
55
|
10
|
11.6
|
5.1
|
≤37
|
18
|
55
|
12
|
5
|
1.0
|
1.0
|
0.10.0
|
iterable_allowed |
39
|
14
|
52
|
No
|
26
|
10
|
39
|
39
|
52
|
26
|
10
|
4.0
|
1.0
|
4.0.0
|
new_required |
7
|
14
|
44
|
No
|
15
|
5.1
|
≤37
|
18
|
44
|
14
|
5
|
1.0
|
1.0
|
0.12.0
|
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]);
See also
© 2005–2022 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Float32Array/Float32Array