初学Javascript对象

<script>
    var p=new Object();
    
    //属性
    p.width=300;
    p.height=200;
    p.num=4;
    p.autotime=3;


    //方法
    p.autoplay=function(){
        alert("play....");
    }
    p.test=function(){
    
    }

alert(p.width);

p.autoplay();
</script>

    var test = {
        
        alr:function(){
            var Oul = document.getElementById('ul');
            var Oli = Oul.getElementsByTagName('li');
            for(var i=0;i<Oli.length;i++){
                
                (function(i){
                    Oli[i].onclick=function(){
                        alert(i)
                    }
                })(i);
            }
        }
    }
    
    test.alr();

    function test(){
        
        this.alr=function(){
            var Oul = document.getElementById('ul');
            var Oli = Oul.getElementsByTagName('li');
            for(var i=0;i<Oli.length;i++){
                
                (function(i){
                    Oli[i].onclick=function(){
                        alert(i)
                    }
                })(i);
            }
        }
    }

    
    var Ojc = new test();
    
    Ojc.alr();

    //创建原型对象，定义属性、方法、及对象事件等。 
    Student.prototype={ 
        _name:null,
        _age:null,
        _sex:null,
        ShowName:function()
        {
            alert("Name:"+ this._name +"
" + "Age:" + this._age + "
" + "Sex:"+ this._sex); 
        }
    }
    
    
    //专门用一个函数来初始化对象。 
    function Student(name,age,sex)
    {
        this._name=name; 
        this._age=age; 
        this._sex=sex; 
    }

    var student = new Student("小明",25,"男"); //实例化 
    student.ShowName(); //调用对象方法 

    

    
    var  lp = {
       name:    "Vicky",
       age:     26,
       eat: function() {
              alert('1');
       },
       sleep: function() {
           alert('2');
        }
    };
    
    
    lp.sleep();

    
    var index = 0
    function A(x,y) { 
        this.x = x;
        this.y = y;
        A.prototype.FunX = function(){
            document.body.style.background = 'red'; 
        }; 
        A.prototype.FunY = function(){
            alert(y)
        }; 
    }
    
    var obj = new A(5,10); 
    alert(obj.x); 
    alert(obj.y); 
    obj.FunX(); 
    obj.FunY();