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Float32Array() constructor

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.

The Float32Array() constructor creates Float32Array objects. The contents are initialized to 0 unless initialization data is explicitly provided.

Syntax

new Float32Array()
new Float32Array(length)
new Float32Array(typedArray)
new Float32Array(object)

new Float32Array(buffer)
new Float32Array(buffer, byteOffset)
new Float32Array(buffer, byteOffset, length)

Note: Float32Array() can only be constructed with new. Attempting to call it without new throws a TypeError.

Parameters

See TypedArray.

Exceptions

See TypedArray.

Examples

Different ways to create a Float32Array

// From a length
const 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
const x = new Float32Array([21, 31]);
console.log(x[1]); // 31

// From another TypedArray
const y = new Float32Array(x);
console.log(y[0]); // 21

// From an ArrayBuffer
const buffer = new ArrayBuffer(32);
const z = new Float32Array(buffer, 4, 4);
console.log(z.byteOffset); // 4

// From an iterable
const iterable = (function* () {
  yield* [1, 2, 3];
})();
const float32FromIterable = new Float32Array(iterable);
console.log(float32FromIterable);
// Float32Array [1, 2, 3]

Specifications

Specification
ECMAScript® 2026 Language Specification> # sec-typedarray-constructors>

Browser compatibility

	Desktop					Mobile							Server
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	WebView Android	WebView on iOS	Bun	Deno	Node.js
`Float32Array`	7	12	4	11.6	5.1	18	4	12	4.2	1.0	4	4.2	1.0.0	1.0	0.10.0
`constructor_without_parameters`	7	12	55	11.6	5.1	18	55	12	5	1.0	4.4	5	1.0.0	1.0	0.10.0
`iterable_allowed`	39	14	52	26	10	39	52	26	10	4.0	39	10	1.0.0	1.0	4.0.0