数组的解构赋值

从数组中提取值赋值给变量

var arr = [1,2,3];
var [a, b] = arr;
let [x, y, z] = arr;
let [m, ,n] = arr;

1、简单应用，交换变量的值

let a = 10;
let b = 19;
let [a,b] = [b,a];

数组的赋值需要注意顺序