oh dear-

pardon my ignorance but,
class user{
private $user_id;
private $user_name;
public function __construct($user_id) {
$this -> user_id=$user_id;
$this -> user_name = $result['username'];

what is '$this ->'

>>27
Not at all. The issue was that you believed Java was not an Object Oriented language. I corrected your mistake, and now you are trying to tell me that I am sidestepping "the issue" that Java is not a very good Object Oriented language. One lesson is enough for you today.