ES6的学习--待完成

[Liudongge]

http://www.imooc.com/article/17720?block_id=tuijian_wz

[Liudongge]

let arr = [{key:'001'}, {key:'002'}]
for(let item in arr) console.log(item) // 0  1
for(let item of arr) console.log(item) // {key: "001"} {key: "002"}

for in遍历的是数组的索引 for of遍历的是数组元素值