在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

WeakSet constructor lets you create WeakSet objects that store weakly held objects in a collection.

句法

new WeakSet([iterable]);
					

参数

iterable

If an iterable object is passed, all of its elements will be added to the new WeakSet . null is treated as undefined.

范例

Using the WeakSet object

var ws = new WeakSet();
var foo = {};
var bar = {};
ws.add(foo);
ws.add(bar);
ws.has(foo);    // true
ws.has(bar);    // true
ws.delete(foo); // removes foo from the set
ws.has(foo);    // false, foo has been removed
ws.has(bar);    // true, bar is retained
					

注意， foo !== bar . While they are similar objects, they are not the same object . And so they are both added to the set.

规范

规范
ECMAScript (ECMA-262) The definition of 'WeakSet constructor' in that specification.

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
WeakSet() 构造函数	Chrome 36	Edge 12	Firefox 34	IE No	Opera 23	Safari 9	WebView Android 37	Chrome Android 36	Firefox Android 34	Opera Android 24	Safari iOS 9	Samsung Internet Android 3.0	nodejs 0.12
new WeakSet(iterable)	Chrome 38	Edge 12	Firefox 34	IE No	Opera 25	Safari 9	WebView Android 38	Chrome Android 38	Firefox Android 34	Opera Android 25	Safari iOS 9	Samsung Internet Android 3.0	nodejs 0.12
new WeakSet(null)	Chrome 36	Edge 12	Firefox 37	IE No	Opera 23	Safari 9	WebView Android 37	Chrome Android 36	Firefox Android 37	Opera Android 24	Safari iOS 9	Samsung Internet Android 3.0	nodejs 0.12

图例

完整支持

完整支持

不支持

不支持

另请参阅

• WeakSet

元数据

• 最后修改： 2020 年 1 月 22 日

相关话题

1. 标准内置对象
2. WeakSet
3. 方法
   1. WeakSet.prototype.add()
   2. WeakSet.prototype.clear()
   3. WeakSet.prototype.delete()
   4. WeakSet.prototype.has()
4. 继承：
5. Function
6. 特性
   1. Function.arguments
   2. Function.caller
   3. Function.displayName
   4. Function.length
   5. Function.name
7. 方法
   1. Function.prototype.apply()
   2. Function.prototype.bind()
   3. Function.prototype.call()
   4. Function.prototype.toSource()
   5. Function.prototype.toString()
8. Object
9. 特性
   1. Object.prototype.__proto__
   2. Object.prototype.constructor
10. 方法
    1. Object.prototype.__defineGetter__()
    2. Object.prototype.__defineSetter__()
    3. Object.prototype.__lookupGetter__()
    4. Object.prototype.__lookupSetter__()
    5. Object.prototype.hasOwnProperty()
    6. Object.prototype.isPrototypeOf()
    7. Object.prototype.propertyIsEnumerable()
    8. Object.prototype.toLocaleString()
    9. Object.prototype.toSource()
    10. Object.prototype.toString()
    11. Object.prototype.valueOf()
    12. Object.setPrototypeOf()