Symbols

https://hacks.mozilla.org/2015/06/es6-in-depth-symbols/

 

 1 <script>
 2     function w(wcon) {
 3         console.log(wcon)
 4     }
 5     w(Symbol)
 6     w(Symbol())
 7     w(Symbol("foo") !== Symbol("foo"))
 8     //true
 9     const foo = Symbol()
10     w(foo)
11     const bar = Symbol()
12     typeof foo === "symbol"
13     w(typeof foo === "symbol")
14     //true
15     var sym = Symbol("<3");
16     // "your symbol is " + sym
17     // Uncaught TypeError: Cannot convert a Symbol value to a string
18     w(String(sym))
19     //Symbol(<3)
20     w(sym.toString())
21     //Symbol(<3)
22     w("your symbol is " + String(sym))
23     //your symbol is Symbol(<3)
24     w("your symbol is " + sym.toString())
25     //your symbol is Symbol(<3)
26 </script>

 

posted @ 2017-01-06 10:29  papering  阅读(219)  评论(0)  编辑  收藏  举报