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Map() コンストラクター - JavaScript | MDN
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Map() コンストラクター
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since 2015年7月.
Map() コンストラクターは、 Map オブジェクトを生成します。
構文
js
new Map()
new Map(iterable)
引数
iterable省略可-
Arrayまたは他の反復処理可能なオブジェクトで、要素はキーと値の組です。 (たとえば、[[ 1, 'one' ],[ 2, 'two' ]]のような 2 つの要素を持つ配列。) それぞれのそれぞれのキーと値の組が新しいMapに追加されます。
例
新しい Map の生成
js
const myMap = new Map([
[1, "one"],
[2, "two"],
[3, "three"],
]);
仕様書
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-map-constructor |
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