扩展运算符

将整体字符串、对象等拆成单个元素

let str="这是一个字符串";
let arr=[...str];
console.log(arr);
// ["这", "是", "一", "个", "字", "符", "串"]

扩展运算符 对象/数组

let obj1 = {a:1,b:2,c:3}; 
let obj2 = {...obj1}; 
console.log(obj2);
// {a: 1, b: 2, c: 3}

let arr1 = [1,2,3]; 
let arr2 = [...arr1]; 
console.log(arr2);
// [1, 2, 3]

函数使用 扩展运算符

function fun(...params) {
    console.log(params);
}
fun(1,2,3,4,5)
// [1, 2, 3, 4, 5]

数组插入值 的 运算符操作

let arr = [1,2,3];
arr.push(...[4,5,6,7,8,9]);
console.log(arr);
// [1, 2, 3, 4, 5, 6, 7, 8, 9]