剰余代入 (%=)
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.
剰余代入演算子 (%=) は、変数を右辺のオペランドの値で除算し、剰余を変数に代入します。
試してみましょう
let a = 3;
console.log((a %= 2));
// Expected output: 1
console.log((a %= 0));
// Expected output: NaN
console.log((a %= "hello"));
// Expected output: NaN
構文
js
x %= y; // x = x % y
例
剰余代入の使用
js
// 以下の変数を想定
// bar = 5
bar %= 2; // 1
bar %= "foo"; // NaN
bar %= 0; // NaN
仕様書
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-assignment-operators |