Symbol
ES6 新特性
Compatibility
IE Not Support Chrome 38.0 Firefox 36.0
About iterator
https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Symbol/iterator
ES6 新特性
IE Not Support Chrome 38.0 Firefox 36.0
https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Symbol/iterator