ES6 拓展运算符

/**
 * Created by Administrator on 2017/11/10.
 */

console.log(1,...[2,3,4],5)  //1 2 3 4 5


function add(x, y) {
    return x+y
}
var numbers = [4,38]
a = add(...numbers)
console.log(a)  // 42


function f(x, y, z) {

}
var a =[0,1,2]
f(...a)    //ok  由于扩展运算符可以展开数组，所以不再需要apply方法，将数组转为函数的参数了。

var a=[1,2,3]
var b = [2,3,4]
var c = [...a,...b]
console.log(c)         //  42

const [first,...end] =  [1,2,3,4,5]
// const [first,...end] =  "fooo"
console.log(first) //f    1
console.log(end) //[ 'o', 'o', 'o' ]     [ 2, 3, 4, 5 ]
// console.log(endend)

a = [..."helllo"]  //扩展运算符还可以将字符串转为真正的数组。
console.log(a)   //[ 'h', 'e', 'l', 'l', 'l', 'o' ]