一元負號運算子（-）

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.

一元負號運算子（-）置於運算元之前，並將運算元轉為其負值。

嘗試一下

語法

js
-x

範例

轉換數字

js
const x = 3;
const y = -x;

// y = -3
// x = 3

轉換非數字

一元負號運算子可以將非數字轉為數字。

js
const x = "4";
const y = -x;

// y = -4

規範

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

瀏覽器相容性

BCD tables only load in the browser

參見