ArrayBuffer objects can be made resizable by including the maxByteLength option when calling the ArrayBuffer() constructor. You can query whether an ArrayBuffer is resizable and what its maximum size is by accessing its resizable and maxByteLength properties, respectively. You can assign a new size to a resizable ArrayBuffer with a resize() call. New bytes are initialized to 0.

These features make resizing ArrayBuffers more efficient — otherwise, you have to make a copy of the buffer with a new size. It also gives JavaScript parity with WebAssembly in this regard (WASM linear memory can be resized with WebAssembly.Memory.prototype.grow()).

ArrayBuffer()

Creates a new ArrayBuffer object.

ArrayBuffer[@@species]

The constructor function that is used to create derived objects.

ArrayBuffer.isView()

Returns true if arg is one of the ArrayBuffer views, such as typed array objects or a DataView. Returns false otherwise.

These properties are defined on ArrayBuffer.prototype and shared by all ArrayBuffer instances.

ArrayBuffer.prototype.byteLength

The size, in bytes, of the ArrayBuffer. This is established when the array is constructed and can only be changed using the ArrayBuffer.prototype.resize() method if the ArrayBuffer is resizable.

ArrayBuffer.prototype.constructor

The constructor function that created the instance object. For ArrayBuffer instances, the initial value is the ArrayBuffer constructor.

ArrayBuffer.prototype.maxByteLength

The read-only maximum length, in bytes, that the ArrayBuffer can be resized to. This is established when the array is constructed and cannot be changed.

ArrayBuffer.prototype.resizable

Read-only. Returns true if the ArrayBuffer can be resized, or false if not.

ArrayBuffer.prototype[@@toStringTag]

The initial value of the @@toStringTag property is the string "ArrayBuffer". This property is used in Object.prototype.toString().

ArrayBuffer.prototype.resize()

Resizes the ArrayBuffer to the specified size, in bytes.

ArrayBuffer.prototype.slice()

Returns a new ArrayBuffer whose contents are a copy of this ArrayBuffer's bytes from begin (inclusive) up to end (exclusive). If either begin or end is negative, it refers to an index from the end of the array, as opposed to from the beginning.

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

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

• Polyfill of ArrayBuffer in core-js
• JavaScript typed arrays
• SharedArrayBuffer
• RangeError: invalid array length