WeakMap.prototype.set()

set() 方法根据指定的key和value在 WeakMap对象中添加新/更新元素。

语法

wm.set(key, value);

参数

key
必须的。必须是 对象。是要在 WeakMap 对象中添加元素的key部分。
value
必须的。任意的值。是要在 WeakMap 对象中添加/元素的value部分。

返回值

该WeakMap对象

例子

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

Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
WeakMap.prototype.set		 Standard Initial definition.
ECMAScript Latest Draft (ECMA-262)
WeakMap.prototype.set		 Draft

浏览器兼容

Update compatibility data on GitHub
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 Full support 36 Edge Full support 12 Firefox Full support 6
Notes
Full support 6
Notes
Notes 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 Partial support 11
Notes
Partial support 11
Notes
Notes Returns 'undefined' instead of the 'Map' object.
Opera Full support 23 Safari Full support 8 WebView Android Full support 37 Chrome Android Full support 36 Firefox Android Full support 6
Notes
Full support 6
Notes
Notes 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 Full support 24 Safari iOS Full support 8 Samsung Internet Android Full support 3.0 nodejs Full support 0.12
Full support 0.12
Full support 0.10
Disabled
Disabled From version 0.10: this feature is behind the --harmony runtime flag.

Legend

Full support  
Full support
Partial support  
Partial support
See implementation notes.
See implementation notes.
User must explicitly enable this feature.
User must explicitly enable this feature.

Firefox-特殊说明

  • 直到Firefox 33 (Firefox 33 / Thunderbird 33 / SeaMonkey 2.30), WeakMap.prototype.set returned undefined 而不支持联式。它已经修复 (bug 1031632). 这样的实现也存在于 Chrome/v8 (issue).

See also

  1. JavaScript 标准库
  2. WeakMap
  3. 属性
    1. WeakMap.prototype
  4. 方法
    1. WeakMap.prototype.clear()
    2. WeakMap.prototype.delete()
    3. WeakMap.prototype.get()
    4. WeakMap.prototype.has()
    5. WeakMap.prototype.set()
  5. 继承
  6. Function
  7. 属性
    1. Function.arguments
    2. Function.arity
    3. Function.caller
    4. Function.displayName
    5. Function.length
    6. Function.name
    7. Function.prototype
  8. 方法
    1. Function.prototype.apply()
    2. Function.prototype.bind()
    3. Function.prototype.call()
    4. Function.prototype.isGenerator()
    5. Function.prototype.toSource()
    6. Function.prototype.toString()
  9. Object
  10. 属性
    1. Object.prototype.__count__
    2. Object.prototype.__noSuchMethod__
    3. Object.prototype.__parent__
    4. Object.prototype.__proto__
    5. Object.prototype.constructor
  11. 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.unwatch()
    12. Object.prototype.valueOf()
    13. Object.prototype.watch()
    14. Object.setPrototypeOf()