对象和数组的解构赋值

Posted 2021-09-15 纸 飞机

按照一定模式，从数组和对象中提取值， 对变量进行赋值。这被称为解构。通俗讲就是怎么快速地从对象和数组中获取到你想要的数据。

解构对象

基本

let {name,age} = {name:"swr",age:28};
console.log(name) //'swr'
console.log(age) //28

使用不同名称

let {name:Name,age} = {name:'swr',age:28}
console.log(Name) // 'swr'
console.log(age) //28

嵌套解构

let person = {
    address: {
        province:'广东',
        city:'深圳'
    }
}
let {address: {province}} = person;
console.log(province) //广东

解构数组

基本

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

嵌套

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

可忽略

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

剩余运算

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

结合数组解构和对象解构

let obj = {
    num: [1,2],
    …
}
let {num: [firstnum, secondnum]} = obj;
console.log(firstnum, secondnum); //1,2