javascript中的遍历for in 以及with的用法

          with(<对象>){

              <语句组>

           }

<script type="text/javascript">
function member(name,gender){
    this.name=name;
    this.gender=gender;
}
function showProperty(obj,objStr){
    var str="";
    for(var i in obj){
        str+=objStr+"."+i+" = "+obj[i]+"<br>"
    }
    return str;
}
var obj =new member("刘若英","女");
//document.write(showProperty(obj,"person"));
with(document){
    write(showProperty(obj,"person"));
}
</script>
/*运行效果:
person.name = 刘若英
person.gender = 女
*/