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左移赋值（<<=）
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since 2015年7月.
左移赋值运算符（<<=）将变量向左移动指定的位数，并将结果赋值给变量。
尝试一下
let a = 5; // 00000000000000000000000000000101a <<= 2; // 00000000000000000000000000010100console.log(a);// Expected output: 20语法
js
x <<= y // x = x << y示例
使用左移赋值
js
let a = 5;// 00000000000000000000000000000101a <<= 2; // 20// 00000000000000000000000000010100规范
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-assignment-operators |