ES6中另外一个好玩的特性就是Spread Operator 也是三个点儿...接下来就展示一下它的用途。
组装对象或者数组
const arr1 = ['red', 'yellow']
const arr2 = [...arr1, 'green', 'pink']
console.log(arr2) //["red", "yellow", "green", "pink"]
const obj1 = { fist: 'a', second: 'b'}
const obj2 = { ...obj1, third: 'c' }
console.log(obj2) //{fist: "a", second: "b", third: "c"}