Map.prototype.clear()
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.
clear() メソッドは Map オブジェクトからすべての要素を削除します。
試してみましょう
const map1 = new Map();
map1.set("bar", "baz");
map1.set(1, "foo");
console.log(map1.size);
// Expected output: 2
map1.clear();
console.log(map1.size);
// Expected output: 0
構文
js
clear()
返値
例
clear() の使用
js
const myMap = new Map();
myMap.set("bar", "baz");
myMap.set(1, "foo");
console.log(myMap.size); // 2
console.log(myMap.has("bar")); // true
myMap.clear();
console.log(myMap.size); // 0
console.log(myMap.has("bar")); // false
仕様書
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-map.prototype.clear |