关于javascript:for-in-和-hasOwnProperty的区别

for in能够遍历所有可枚举属性以及原型上的属性

var createObj = function(){    this.name = "大表哥";}var obj1 = new createObj();createObj.prototype.age = 10;for(var p in obj1){    console.log('key:',p);    console.log('value:',obj1[p]);}

输入后果

key: namevalue: 大表哥key: agevalue: 10

hasOwnProperty()不会从原型上寻找属性

var resName = obj1.hasOwnProperty("name");console.log("name",resName);var resAge = obj1.hasOwnProperty("age");console.log("age",resAge);

输入后果

name trueage false