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WeakMap.prototype.set() - JavaScript | MDN

Baseline Widely available

WeakMap 实例的 set() 方法根据指定的键值在该 WeakMap 中添加新元素。

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"

key

必须是对象或非全局注册的符号。要添加到 WeakMap 对象的元素的键。

value

任何要添加到 WeakMap 对象的元素的值。

该 WeakMap 对象

TypeError

如果 key 不是一个对象或非全局注册的符号，则抛出该异常。

const wm = new WeakMap();
const obj = {};

// 将新元素添加到 WeakMap
wm.set(obj, "foo").set(window, "bar"); // 链式调用

// 更新 WeakMap 中的元素
wm.set(obj, "baz");

// 使用非全局注册的符号作为键
const sym = Symbol("foo");
wm.set(sym, "baz");
wm.set(Symbol.iterator, "qux");

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