//使用原型工厂封装继承
function extend(sub,sup){
    sub.prototype=Object.create(sup.prototype);
    Object.defineProperty(sub.prototype,"constructor",{
        value:sub,
        enumerable:false
    });
}

function User(name,age){
    this.name=name;
    this.age=age;
}

User.prototype.show=function(){
    console.log(this.name,this.age);
}

function Admin(...args){
    User.apply(this,args);
}

extend(Admin,User);
let admin=new Admin('xj',12);
admin.show();