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.
WeakMap 实例的 set() 方法根据指定的键值在该 WeakMap 中添加新元素。
尝试一下
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"
语法
js
set(key, value)
参数
返回值
该 WeakMap 对象
异常
示例
使用 set() 方法
js
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");
规范
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-weakmap.prototype.set |