用反射机制和prototype实现继承

<script type="text/javascript">function People(){this.name='chenmin';this.sex='girl';this.age=22;this.speak=function(){alert('qzuishuai')}}People.prototype.skill='walk';function Woman(){}for(var arr in People.prototype){Woman.prototype[arr]=People.prototype[arr];} //通过for in迭代 反射 一一对应的进行赋值 ；//从而实现让Woman继承People原型上的属性方法；Woman.prototype.wb='kawayi';var nvren=new Woman();alert(nvren.name);//undefinedalert(nvren.skill);//walkalert(nvren.wb);//kawayi</script>