`byteLength` 属性描述了视图从它的 `ArrayBuffer` 开始的字节长度。

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## 语法

    dataview.byteLength

## 描述

`byteLength` 属性是一个获取(accessor)属性，它的 set 属性为 undefined，这意味着它是只读的。值在 `DataView 被创建时就确定了，且不能改变。如果` `DataView` 没有指定偏移量或byteLength，那么被引用的 `ArrayBuffer 的字节长度将被返回。`

## Examples

### Using the `byteLength` property

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

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

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

## 规范

Specification | Status | Comment
--- | --- | ---
ECMAScript 2015 (6th Edition, ECMA-262) DataView.prototype.byteLength | Standard | Initial definition.
ECMAScript Latest Draft (ECMA-262) DataView.prototype.byteLength | Draft |

## 浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

| Desktop | Mobile | Server
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | Safari on iOS | Samsung Internet | Node.js
`byteLength` | Chrome Full support 9 | Edge Full support 12 | Firefox Full support 15 | IE Full support 10 | Opera Full support 12.1 | Safari Full support 5.1 | WebView Android Full support 4 | Chrome Android Full support Yes | Edge Mobile Full support Yes | Firefox Android Full support 15 | Opera Android Full support 12 | Safari iOS Full support 4.2 | Samsung Internet Android Full support Yes | nodejs Full support Yes

### Legend

Full support
  Full support

## 相关链接

- `DataView`
- `ArrayBuffer`