typedArray.byteLength

The byteLength accessor property represents the length (in bytes) of a typed array.

Syntax

typedarray.byteLength

Description

The byteLength property is an accessor property whose set accessor function is undefined, meaning that you can only read this property. The value is established when a TypedArray is constructed and cannot be changed. If the TypedArray is not specifying an byteOffset or a length, the length of the referenced ArrayBuffer will be returned. TypedArray is one of the TypedArray objects.

Examples

Using the byteLength property

var buffer = new ArrayBuffer(8);

var uint8 = new Uint8Array(buffer);
uint8.byteLength; // 8 (matches the byteLength of the buffer)

var uint8 = new Uint8Array(buffer, 1, 5);
uint8.byteLength; // 5 (as specified when constructing the Uint8Array)

var uint8 = new Uint8Array(buffer, 2);
uint8.byteLength; // 6 (due to the offset of the constructed Uint8Array)

Specifications

Specification	Status	Comment
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'TypedArray.prototype.byteLength' in that specification.	Standard	Initial definition.
ECMAScript 2017 Draft (ECMA-262) The definition of 'TypedArray.prototype.byteLength' in that specification.	Draft

Browser compatibility

See also

• JavaScript typed arrays
• TypedArray