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

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。

返回值

WeakMap 对象

异常

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。

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® 2025 Language Specification
# sec-weakmap.prototype.set

浏览器兼容性

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
set

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
See implementation notes.

参见