htmlspecialchars($_POST["username"]), "password" => htmlspecialchars($_POST["password"]), "password_confirm" => htmlspecialchars($_POST["password_2"]), ]; $register = new Register($form->username, $form->password, $conn); $register->checkUsername(); $register->checkPassword($form->password_confirm); if ($register->error == NULL) { $register->insertUser(); header("Location: /"); } } ?>

Duck register username: password: confirm password: error != NULL) echo "$register->error "; ?>