js数据解构

1、变量比值多可以设置变量默认值 解构

let [a,b,c,d='aaa']=[12,34,24]

2、变量比值少可以用剩余参数解构

let [a,...b]=[11,22,44,55] //a 11 b [22,44,55]

3、按需赋值

let [a,,b]=[5,6,9]

4、数组嵌套解构

let [a,b,arr]=[1,2,[5,8,9]]

let [a,b,[c,d,e]]=[1,2,[5,8,9]]

5、数组嵌套对象

let person=[{name:'howhy',score:{math:0,english:78,chinese:77}}]

let [{name,score:{math,chinese,english}}]=person

6、对象解构

let obj={name:'use1',age:12}

let {name,age}=obj

let {name:uname,age}=obj

let student={name:'zhangsan',score:{math:90,english:88,chinese:87}}

let {name,score:{math,chinese,english}}=student