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DataView.prototype.byteLength

The byteLength accessor property of DataView instances returns the length (in bytes) of this view.

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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 an DataView is constructed and cannot be changed. If the DataView is not specifying an offset or a byteLength, the byteLength of the referenced ArrayBuffer or SharedArrayBuffer will be returned.

Examples

Using the byteLength property

const buffer = new ArrayBuffer(8);
const dataview = new DataView(buffer);
dataview.byteLength; // 8 (matches the byteLength of the buffer)

const dataview2 = new DataView(buffer, 1, 5);
dataview2.byteLength; // 5 (as specified when constructing the DataView)

const dataview3 = new DataView(buffer, 2);
dataview3.byteLength; // 6 (due to the offset of the constructed DataView)

Specifications

Specification
ECMAScript Language Specification # sec-get-dataview.prototype.bytelength

Browser compatibility

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	WebView Android	Deno	Node.js
`byteLength`	9	12	15	12.1	5.1	18	15	12.1	5	1.0	4	1.0	0.10.0