weakMap.get
weakMap.get
get()
方法返回 WeakMap
指定的元素。
语法
wm.get(key
参数
key必须。 想要从 WeakMap
获取的元素的键。
返回值
返回与指定键相关联的值,如果 WeakMap 对象找不到这个键则返回 undefined。
示例
使用get 方法
var wm = new WeakMap(
wm.set(window, 'foo'
wm.get(window // Returns "foo".
wm.get('baz' // Returns undefined.
规范
Specification | Status | Comment |
---|---|---|
ECMAScript 2015 (6th Edition, ECMA-262)The definition of 'WeakMap.prototype.get' in that specification. | Standard | Initial definition. |
ECMAScript Latest Draft (ECMA-262)The definition of 'WeakMap.prototype.get' in that specification. | Draft | |
浏览器兼容性
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | 36 | (Yes) | 6.0 (6.0) | 11 | 23 | 7.1 |
Feature | Android | Edge | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | No support | (Yes) | 6.0 (6.0) | No support | No support | 8 |