ES6解构赋值详解：数组、对象、嵌套与默认值

const arr = ['dasha', 'ersha', 'gangdan']
let [a, b, c] = arr	//a='dasha' b='ersha' c='gangdan'
//假如需要交换ab的值 只需要
[a, b] = [b, a]

const arr = [1, [2,3,4], 5]
let [a, [b,,d], c] = arr

console.log(a)	// 1
console.log(b)	// 2
console.log(d) 	// 4

let [a=1] = [100] // a=100
let [b=1] = [] // b=1

const obj = {
    name:'shabi',
    age:12,
}
let{age} = obj

// 为了防止age在上面被let定义过了，可以将age改名为ag
let{age:ag, err="定义err默认值即使对象中没有这个属性，也可以获取到这个默认值字符串"} = obj
console.log(err)// '定义err默认值即使对象中没有这个属性，也可以获取到这个默认值字符串'

function test(){
    return [1,2,3]
}
let [x,y] = test()
console.log(x)	//x = 1
console.log(y)	//y = 2

let [a,...rest] = [1, 2, 3];
console.log(a); // 1
console.log(rest); // [2, 3]