What are the potential reasons for a user not being logged out after clicking the logout button in a PHP script?

The potential reasons for a user not being logged out after clicking the logout button in a PHP script could include not destroying the session properly, not redirecting the user to a different page after logout, or not clearing the session variables. To solve this issue, make sure to call session_destroy() to destroy the session data, unset any session variables that may still be set, and redirect the user to a different page after logout.

<?php
session_start();

// Unset all session variables
$_SESSION = array();

// Destroy the session
session_destroy();

// Redirect the user to a different page
header("Location: index.php");
exit;
?>