ArrayBuffer.prototype.byteLength

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

ArrayBuffer 实例的 byteLength 访问器属性返回该数组缓冲区的长度（以字节为单位）。

尝试一下

// Create an ArrayBuffer with a size in bytes
const buffer = new ArrayBuffer(8);

// Use byteLength to check the size
const bytes = buffer.byteLength;

console.log(bytes);
// Expected output: 8

描述

byteLength 属性是一个访问器属性，它的 set 访问器函数是 undefined，这意味着你只能读取这个属性。该值在数组创建时确定，并且无法修改。如果这个 ArrayBuffer 被分离，则此属性返回 0。

示例

使用 byteLength

const buffer = new ArrayBuffer(8);
buffer.byteLength; // 8

规范

Specification
ECMAScript® 2025 Language Specification # sec-get-arraybuffer.prototype.bytelength

浏览器兼容性

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参见

ArrayBuffer