1、扩展运算符:
<script> //扩展运算符 ... //1、将非数组变成数组(类数组 即有length属性的) //2、将数组变成非数组 //1、将非数组变成数组(类数组 即有length属性的) let str = '123'; console.log([...str]); function f() { console.log([...arguments]); } f(1,12,369); function f1(...arg) { console.log(arg); } f1(10,20,30); //2、将数组变成非数组 let a1 = [1,2,3,4,5,6]; let a2 = [7,8,9,]; console.log(a1.concat(a2));//直接连接 console.log([...a1, ...a2]);//解构后放在一起,先将数组转为非数组 console.log(Math.max(...a1));//数组解构,将数组变成非数组,然后调用方法取最大值 console.log(...a1);//将数组解构输出,1 2 3 4 5 6 </script>