乗算 (*)

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.

乗算演算子 (*) はオペランドの積を生成します。

試してみましょう

console.log(3 * 4);
// Expected output: 12

console.log(-3 * 4);
// Expected output: -12

console.log("3" * 2);
// Expected output: 6

console.log("foo" * 2);
// Expected output: NaN

構文

js
x * y;

例

数値を用いた乗算

js
2 * 2; // 4
-2 * 2; // -4

無限大との乗算

js
Infinity * 0; // NaN
Infinity * Infinity; // Infinity

非数との乗算

js
"foo" * 2; // NaN

仕様書

Specification
ECMAScript® 2025 Language Specification
# sec-multiplicative-operators

ブラウザーの互換性

BCD tables only load in the browser

関連情報