javascript拷贝

 　　 function copy(obj){   //浅拷贝
         var result = {};
         for(var attr in obj){
             result[attr] = obj[attr];
         }
         return result;
     }

     function copy(obj){   //深拷贝
         var result = {};
         for(var attr in obj){
             if(typeof obj[attr] == 'object'){
                 result[attr] = copy(obj[attr]);
             }
             else{
                 result[attr] = obj[attr];
             }
         }
         return result;
     }