phpstorm - Undefined variable in PHP when the variable is present -

i have looked @ other questions , none of them fixed issue. following class defines variable , calls variable in html code. i've used same method php page , works perfectly. reason not work on page. i've done numerous times no issues. phpstorm says variable $user "might not have been defined" know is. how can fix this? have tried setting variable global @ top of page no luck. have tried setting variable global after if(isset()) , still doesn't work. here's php code:

    <?php session_start(); require_once 'includes/class.user.php'; $user_edit = new user();  if(!$user_edit->is_logged_in()) {     $user_edit->redirect('index.php'); }  if(isset($_get['user_id'])) {     $tid = $_get['user_id'];     $stmt = $user_edit->runquery("select * users user_id = :id");     $stmt->execute(array(':id' => $tid));     $user = $stmt->fetch(pdo::fetch_assoc); } ?>  <?php include('header.php'); ?>      <div class="container side-collapse-container">         <p><?php if (!empty($user['username'])) {                 echo $user['username'];             } ?></p>     </div>  <?php include('footer.php'); ?> 

edit

this shown in browser after running xampp

notice: undefined variable: user in c:\users\user\phpstormprojects\site1\view_user.php on line 22

this should comment, don't have rep yet.

phpstorm saying $user variable might not defined because set in 'if' block. if want phpstorm msg go away, define $user above 'if' array.

$user = []; if (isset($_get['user_id'])) {     $tid = $_get['user_id'];     $stmt = $user_edit->runquery("select * users user_id = :id");     $stmt->execute(array(':id' => $tid));     $user = $stmt->fetch(pdo::fetch_assoc); } 

if user name not showing on page, query either returning empty (false) or index 'username' incorrect.

of course, $user populated, user_id needs in query string.