WeakMap.prototype.set()
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.
set() メソッドは、指定されたキーと値をもつ新しい要素を WeakMap オブジェクトへ追加します。
試してみましょう
const weakmap1 = new WeakMap();
const object1 = {};
const object2 = {};
weakmap1.set(object1, "foo");
weakmap1.set(object2, "bar");
console.log(weakmap1.get(object1));
// Expected output: "foo"
console.log(weakmap1.get(object2));
// Expected output: "bar"
構文
wm.set(key, value);
引数
返値
WeakMap オブジェクトです。
例
set() メソッドの使用
js
var wm = new WeakMap();
var obj = {};
// Add new elements to the WeakMap
wm.set(obj, "foo").set(window, "bar"); // chainable
// Update an element in the WeakMap
wm.set(obj, "baz");
仕様書
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-weakmap.prototype.set |