在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

set() method adds a new element with a specified key and value 到 WeakMap 对象。

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

句法

wm.set(key, value);
					

参数

key

Required. Must be object . The key of the element to add to the WeakMap 对象。

value

Required. Any value. The value of the element to add to the WeakMap 对象。

返回值

WeakMap 对象。

范例

使用 set 方法

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');
					

规范

规范
ECMAScript (ECMA-262) The definition of 'WeakMap.prototype.set' 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
set	Chrome 36	Edge 12	Firefox 6 6 Prior to Firefox 38, this method threw a TypeError when the key parameter was not an object. This has been fixed in version 38 and later to return false as per the ES2015 standard.	IE 部分支持 11 部分支持 11 Returns 'undefined' instead of the 'Map' object.	Opera 23	Safari 8	WebView Android 37	Chrome Android 36	Firefox Android 6 6 Prior to Firefox 38, this method threw a TypeError when the key parameter was not an object. This has been fixed in version 38 and later to return false as per the ES2015 standard.	Opera Android 24	Safari iOS 8	Samsung Internet Android 3.0	nodejs 0.12 0.12 0.10 Disabled Disabled From version 0.10: this feature is behind the --harmony runtime flag.

图例

完整支持

完整支持

部分支持

部分支持

见实现注意事项。

用户必须明确启用此特征。

用户必须明确启用此特征。

另请参阅

• WeakMap
• WeakMap.prototype.get()
• WeakMap.prototype.has()

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. WeakMap
3. 方法
   1. WeakMap.prototype.clear()
   2. WeakMap.prototype.delete()
   3. WeakMap.prototype.get()
   4. WeakMap.prototype.has()
   5. WeakMap.prototype.set()
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()