js遍历数组和遍历对象的区别

<script>  
    //----------------for用来遍历数组对象--  
    var i,myArr = [1,2,3];  
    for (var i = 0; i < myArr.length; i++) {  
        console.log(i+":"+myArr[i]);  
    };  
    //---------for-in 用来遍历非数组对象  
    var man ={hands:2,legs:2,heads:1};  
    //为所有的对象添加clone方法，即给内置原型(object,Array,function)增加原型属性,该方法很强大，也很危险  
    if(typeof Object.prototype.clone ==="undefined"){  
        Object.prototype.clone = function(){};      
    }  
    //  
    for(var i in man){  
        if (man.hasOwnProperty(i)) { //filter,只输出man的私有属性  
            console.log(i,":",man[i]);  
        };  
    }  
    //输出结果为print hands:2,legs:2,heads:1  
  
    for(var i in man) {//不使用过滤  
        console.log(i,":",man[i]);  
    }      
    //输出结果为  
    //hands : 2 index.html:20  
    //legs : 2 index.html:20  
    //heads : 1 index.html:20  
    //clone : function (){}   
    for(var i in man) {  
        if(Object.prototype.hasOwnProperty.call(man,i)) { //过滤  
            console.log(i,":",man[i]);  
        }  
    }  
   //输出结果为print hands:2,legs:2,heads:1  
</script>