创建构造函数的几种方式

<script>
//    创建构造函数的几种方式：
//1.传入参数
   function Product(name){
       this.name=name;
   }
    Product.prototype={};
    var iphone=new Product('iphone9s');
    console.log(iphone.name);//iphone9s;
//2.设置默认值
    function Product(){
        this.name='';
        this.price=0;
    }
    Product.prototype={}
    var iphone=new Product();
    iphone.description="111";
    iphone.images=[];
//3.传入参数和设置默认值混合
    function Product(name,price) {
        this.name = name;
        this.price = price;
        this.version = 1.0;
        this.add = function () {};
    };
    Product.prototype={};
//    4.动态添加形式
    var iphone=new Product();
    iphone.description='111';
    iphone.images=[];
    console.log(iphone instanceof Product)//true
</script>