javascript 原型及继承

一般继承方式如下
function people(n){
     this.name =n;
}

function worker(name,num){
    people.call(this, name);
    this.num =num;
}

worker.prototype =new people()
worker.prototype.constructor = worker

1 原型方式比较灵活
function people(n){
     this.name =n;
}
可以先生成对象，然后添加原型方法
var p1 = new people('zj')
people.prototype.show = function(){
        console.log(this.name)    
}
p1.show()//正确

但是原型重写就有可能有问题
function people(n){
     this.name =n;
}
var p1 = new people('zj')
people.prototype ={
       show:function(){
        console.log(this.name)    
    }
}
var p2 = new people('zj2')
p1.show()//error，没有这个方法，因为prototype被覆盖了
p2.show()//正确