圆括号运算符

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.

圆括号运算符 ( ) 用于控制表达式中的运算优先级。

尝试一下

console.log(1 + 2 * 3); // 1 + 6
// Expected output: 7

console.log(1 + 2 * 3); // 1 + 6
// Expected output: 7

console.log((1 + 2) * 3); // 3 * 3
// Expected output: 9

console.log(1 * 3 + 2 * 3); // 3 + 6
// Expected output: 9

语法

js
(expression)

说明

圆括号运算符由一对圆括号组成,包裹表达式和子表达式用来覆盖常规的运算符优先级,达到低优先级的表达式比高优先级的表达式更早运算。

示例

下面的代码展示了加法运算先于乘法运算的情况。

js
const a = 1;
const b = 2;
const c = 3;

// 默认优先级
a + b * c; // 7
// 默认运算顺序同下
a + (b * c); // 7

// 现在优先考虑乘法之前的加法
(a + b) * c; // 9

// 这相当于
a * c + b * c; // 9

规范

Specification
ECMAScript® 2025 Language Specification
# sec-grouping-operator

浏览器兼容性

Report problems with this compatibility data on GitHub
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
Grouping operator ()

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

参见