js for in

 var ob={
            name:'name',array:["1","2"],age:1
        };


        ob.array2=function () {
            for(var i=0;i<this.array.length;i++)
            {
                document.writeln(this.array[i]);
            }
        }

       ob.array2()

        var a;
        for(a in ob)
        {
            console.log(ob[a])
        }

for in 用于取出对象所有的属性和方法