减法（-）

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.

减法（-）运算符将两个操作数相减，并产生两者之差。

尝试一下

语法

js
x - y

描述

减法运算符将两个操作数转换为数值，并根据两个操作数的类型执行数字减法或 BigInt 减法。如果类型不匹配，则抛出 TypeError。

示例

数值减法

js
// Number - Number -> subtraction
5 - 3; // 2

// Number - Number -> subtraction
3 - 5; // -2

非数值减法

js
// String - Number -> subtraction
"foo" - 3; // NaN; "foo" is converted to the number NaN

// Number - String -> subtraction
5 - "3"; // 2; "3" is converted to the number 3

BigInt 减法

js
// BigInt - BigInt -> subtraction
2n - 1n; // 1n

你不能在减法中混合使用 BigInt 和数字操作数。

js
2n - 1; // TypeError: Cannot mix BigInt and other types, use explicit conversions
2 - 1n; // TypeError: Cannot mix BigInt and other types, use explicit conversions

规范

Specification
ECMAScript Language Specification
# sec-subtraction-operator-minus

浏览器兼容性

BCD tables only load in the browser

参见