es6中Array对象的扩展运算符...的使用

es6中Array对象中新增的扩展运算符 ...,将一个数组转为用逗号分隔的参数序列

基本使用

console.log(...[1,2,3])// 1  2  3

函数传参

function add(x,y){
    return x+y;
}

let arr = [4,5];

let num = add(...arr);
console.log(num);//9

合并多个数组

let a = [1,2,3];
let b = [2,3,4];
let c = [5,6,7];

console.log([...a,...b,...c]);//[1, 2, 3, 2, 3, 4, 5, 6, 7]

复制对象

let p1 = {name:'张三',age:1};

let p2 = {...p1};

console.log(p2);//{name:'张三',age:1}

合并对象

合并两个对象，并且key值相同的话，后面的会覆盖掉前面的

let p1 = {name:'张三',age:1};

let p2 = {...p1,name:'李四',sex:'男'};

console.log(p2);//{name: "李四", age: 1, sex: "男"}