Javascript-展开语法

展开数组

const num = [1,2,3];
console.log(...num); //打印数组元素1,2.3

数组合并

let a = [1,2,3];
let b = ['a','nice',...a];//使用...可将a合并到b数组
console.log(b);//[ 'a', 'nice', 1, 2, 3 ]

展开对象

const career = {career:"Student"};
const hobby = {hobby: "game,music,programing"};
const who = {name:"meowrain",...career,...hobby};
console.log(who);//{ name: 'meowrain', career: 'Student', hobby: 'game,music,programing' }

函数传参

使用...name来接收任意数量的参数

function change(...args) {
    console.log(args);
}
change(1,2,3,4,5,'ww');//[ 1, 2, 3, 4, 5, 'ww' ]

案例：

let sum = (x, y, z) => {
    return x + y + z;
} //创建名为sum的函数
const num = [1,2,3];
console.log(...num); //1,2.3
console.log(sum(...num));//传参1,2,3