【学习】js学习笔记：对象的遍历和封装特性

1、对象的属性访问：

对象.属性

对象[属性]，但中括号中必须是字符串

2、属性的遍历：

for in方法举例：

var ren={};

ren.name="名字";

ren.eat=function(){

         alert("吃饭");

         }

for(var i in ren){

         alert(ren[i]);

         }

3、封装-工厂函数，这种方式格式不规范

function dianshi(color,size,brand){

                   var tv={};

                   tv.color=color;

                   tv.size=size;

                   tv.brand=brand;

                   tv.play=function(){

                            alert("玩");

                            }

                   tv.look=function(){

                            alert("看");

                            }

                   return tv;

                   }

         var d1=dianshi("red","42cun","sony");

         var d2=dianshi("blue","40cun","长虹");

         var d3=dianshi("green","30cun","康佳");     

         alert(d1.color);

         alert(d2.size);

         alert(d3.brand);

4、封装-构造函数，这种方式格式更正式

function tv(color,size,brand){          

                   this.color=color;

                   this.size=size;

                   this.brand=brand;

                   this.play=function(){

                            alert("玩");

                            }

                   this.look=function(){

                            alert("看");

                            }

                   }

         var d1=new tv("red","42cun","sony");

         var d2=new tv("blue","40cun","长虹");

         var d3=new tv("green","30cun","康佳");      

         alert(d1.color);

         alert(d2.size);

         alert(d3.brand);

5、封装-代码段

prototype方法：将共有的方法和属性添加到代码段中

function tv(color,size,brand){          

                   this.color=color;

                   this.size=size;

                   this.brand=brand;            

                   this.look=function(){

                            alert("看");

                            }

                   }

         tv.prototype.play=function(){

                            alert("玩");

                            }

         var d1=new tv();

         d1.play();

6、混合方法：几种方式的混合，扬长避短

function tv(color,size,brand){          

                   this.color=color;

                   this.size=size;

                   this.brand=brand;            

                   this.look=function(){

                            alert("看");

                            }

                   }

         tv.prototype.obj={name:"名字"}    

         tv.prototype.play=function(){

                            alert("玩");

                            }

         var d1=new tv();

         d1.play();

         alert(d1.obj.name);