if (!isset($_SESSION['user_id'])) { header("Location: login.php"); exit(); }
if (isset($_POST['submit'])) { // code to submit form data to a database or email header("Location: thank-you.php"); exit(); }Both of these examples use the PHP built-in function, header(), to redirect users to a specified URL or action. Package libraries that can be used with PHP Redirect toAction include Laravel, Yii, and CodeIgniter. These packages provide additional functionality and features for web developers to use in their projects.