減算 (-)
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.
減算演算子 (-) は 2 つのオペランドの間で減算し、それらの差を生成します。
試してみましょう
console.log(5 - 3); // Expected output: 2 console.log(3.5 - 5); // Expected output: -1.5 console.log(5 - "hello"); // Expected output: NaN console.log(5 - true); // Expected output: 4 構文
js
x - y; 例
数値の減算
js
5 - 3; // 2 3 - 5; // -2 非数の減算
js
"foo" - 3; // NaN 仕様書
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-subtraction-operator-minus |
