<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>