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>