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 July 2015.

简单赋值运算符(=)用于给变量赋值。赋值表达式本身的值为要赋值的值。为了将一个值赋给多个变量,可以链式使用赋值运算符。

尝试一下

let x = 2;
const y = 3;

console.log(x);
// Expected output: 2

console.log((x = y + 1)); // 3 + 1
// Expected output: 4

console.log((x = x * y)); // 4 * 3
// Expected output: 12

语法

js
x = y

示例

简单赋值和链式赋值

js
// 假设已经存在以下变量
//  x = 5
//  y = 10
//  z = 25

x = y; // x 为 10
x = y = z; // x, y 都为 25

规范

Specification
ECMAScript® 2025 Language Specification
# sec-assignment-operators

浏览器兼容性

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desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
Assignment (x = y)

Legend

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Full support
Full support

参见