weakSet.add
weakSet.add
add() 方法在 WeakSet 对象的最后一个元素后添加新的对象。
语法
ws.add(value
参数
value必须。 将对象添加进 WeakSet集合中。
返回值
WeakSet 对象。
使用 add 方法
var ws = new WeakSet(
ws.add(window // add the window object to the WeakSet
ws.has(window // true
// Weakset only takes objects as arguments
ws.add(1
// results in "TypeError: Invalid value used in weak set" in Chrome
// and "TypeError: 1 is not a non-null object" in Firefox
规范
| Specification | Status | Comment |
|---|---|---|
| ECMAScript 2015 (6th Edition, ECMA-262)The definition of 'WeakSet.prototype.add' in that specification. | Standard | Initial definition. |
| ECMAScript Latest Draft (ECMA-262)The definition of 'WeakSet.prototype.add' in that specification. | Draft | |
浏览器兼容性
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
| Basic support | 36 | (Yes) | 34 (34) | No support | 23 | No support |
| Feature | Android | Edge | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|
| Basic support | No support | (Yes) | 34.0 (34) | No support | No support | No support |
