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;
    }