ArrayBuffer : Object

constructor

ArrayBuffers are fixed length buffer of bytes. The bytes in an ArrayBuffer are only accessible through a DataView (for heterogenous data) or one of the typed arrays (for homogeneous data): BigInt64Array, BigUint64Array, Float32Array, Float64Array, Int8Array, Int16Array, Int32Array, Uint8Array, Uint8ClampedArray, Uint16Array, Uint32Array. Multiple DataView and typed arrays can be applied to one ArrayBuffer and changes to one view can be seen in the others immediately.

Spec

Constructors

new ArrayBuffer(byteLength : Number) : ArrayBuffer

Allocates a new ArrayBuffer of the specified length where each byte starts as 0.

Example:

var buffer = new ArrayBuffer(12);
var dataView = new DataView(buffer);
var int8View = new Int8Array(buffer);
dataView.setInt32(0, 0x1234ABCD);
console.log(dataView.getInt32(0).toString(16)); 
console.log(dataView.getInt8(0).toString(16)); 
console.log(int8View[0].toString(16));

Run

Results:

Instance Properties

byteLength : Number readonly

The length of this in bytes.

Example:

var buffer = new ArrayBuffer(12);
console.log(buffer.byteLength);

Run

Results:

Instance Methods

slice(beginByte : Number, [endByte : Number]) : ArrayBuffer

Creates a new ArrayBuffer with a copy of the bytes of this between beginByte (inclusive) and endByte (exclusive). If endByte is not specified, this.byteLength is used. Changes to this do not affect the copy returned by slice.

Example:

var buffer = new ArrayBuffer(12);
var x = new Int32Array(buffer);
x[1] = 1234;
var slice = buffer.slice(4);
var y = new Int32Array(slice);
console.log(x[1]); 
console.log(y[0]);
x[1] = 6789;
console.log(x[1]); 
console.log(y[0]);

Run

Results:

ArrayBuffer Methods

isView(value : Object) : Boolean

Returns true if value is an ArrayBufferView.

Example:

console.log(ArrayBuffer.isView(new Int32Array()));
console.log(ArrayBuffer.isView(new Float64Array()));
console.log(ArrayBuffer.isView(new Array()));

Run

Results:

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