相信大家对解构赋值并不陌生：
阮大佬ECMAScript 6 入门
里面有讲七种用途，用得最多莫过于json数据处理

json数据处理

let jsonData = {  id: 42,  status: "OK",  data: [867, 5309]};let { id, status, data: number } = jsonData;console.log(id, status, number);// 42, "OK", [867, 5309]

当然变换变量的值，也是用得较多的。

交换变量的值

let x = 1;let y = 2;[x, y] = [y, x];
let x3 = "a";let y3 = "b";let z3 = "c";[x3,y3,z3] = [z3,y3,x3];console.log(x3,y3,z3);//c,b,a

for..of中使用

const arrC = ["a", "b"];for(const [index, element] of arrC.entries()){    console.log(index,element);}//0 "a"//1 "b"

还可以对象解构原始值(字符长度等。。)

const {length: len} = "abc";console.log(len);//3

对象的剩余属性构造

const objA = {a: 1, b: 2, c: 3};const {a:propValue, ...remaining}= objA;console.log(propValue,remaining);//1 {b: 2, c: 3}

remaining被分配一个对象，该对象具有在模式中未提及其键的所有数据属性。

数组的剩余属性构造

const [xx,yy,...rest] = ["a","b","c","d"];console.log(xx,yy,rest);//a b ["c","d"]

rest被分配一个对象，该数组具有在模式中未提及的所有元素。

数组解构：返回数组的操作

const  [,year,month,day] = /^([0-9]{4})-([0-9]{2})-([0-9]{2})$/.exec('2999-12-31')console.log(/^([0-9]{4})-([0-9]{2})-([0-9]{2})$/.exec('2999-12-31'));//["2999-12-31", "2999", "12", "31", index: 0, input: "2999-12-31", groups: undefined]console.log(year,month,day);//2999 12 31

处理函数返回结果

function findElement(arr, predicate) {   for (let index=0; index < arr.length; index++) {        const value = arr[index];        if (predicate(value)) {            return { value, index };        }    }    return { value: undefined, index: -1 };}const arrD = [7, 8, 6];// const {value, index} = findElement(arrD, x => x % 2 === 0);//可以一起输出，也可以单个解构输出const {value} = findElement(arrD, x => x % 2 === 0);const {index} = findElement(arrD, x => x % 2 === 0);console.log(value,index);

参考文献：JavaScript for impatient programmers