<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>