对象扩展运算符

实例1：

function f(...arg){
    console.log(arg[0]);
    console.log(arg[1]);
    console.log(arg[2]);
    console.log(arg[3]);
}

f(1,2,3);

实例2：

let arr1 = ['www','qxb','com'];
let arr2 = [...arr1];
console.log(arr2);
arr2.push('ljj');
console.log(arr2);
console.log(arr1);

rest运算符

实例1：

function f(first,...arg){
    console.log(arg.length);
}

f(0,1,2,3,4,5,6,7);

实例2：

function f(first,...arg){
    for(let val of arg){
        console.log(val);
    }
}

f(0,1,2,3,4,5,6,7);