array session didn't work

[eluser]yudahebat[/eluser]
i've do what you command and its error

Code:

Fatal error: Call to a member function result_array() on a non-object in C:\xampp\htdocs\CI2\system\application\views\v_cart.php on line 23

line 23

Code:

$user_array = $query->result_array();