ArrayBuffer() constructor

The ArrayBuffer() constructor creates ArrayBuffer objects.

Try it

// Create an ArrayBuffer with a size in bytes
const buffer = new ArrayBuffer(8);

console.log(buffer.byteLength);
// Expected output: 8

Syntax

js
new ArrayBuffer(length)
new ArrayBuffer(length, options)

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

Parameters

length

The size, in bytes, of the array buffer to create.

options Optional

An object, which can contain the following properties:

maxByteLength Optional

The maximum size, in bytes, that the array buffer can be resized to.

Return value

A new ArrayBuffer object of the specified size, with its maxByteLength property set to the specified maxByteLength if one was specified. Its contents are initialized to 0.

Exceptions

RangeError

Thrown in one of the following cases:

Examples

undefined

Creating an ArrayBuffer

In this example, we create a 8-byte buffer with an Int32Array view referring to the buffer:

js
const buffer = new ArrayBuffer(8);
const view = new Int32Array(buffer);

Creating a resizable ArrayBuffer

In this example, we create a 8-byte buffer that is resizable to a max length of 16 bytes, then resize() it to 12 bytes:

js
const buffer = new ArrayBuffer(8, { maxByteLength: 16 });

buffer.resize(12);

Note: It is recommended that maxByteLength is set to the smallest value possible for your use case. It should never exceed 1073741824 (1GB) to reduce the risk of out-of-memory errors.

Specifications

See also