What are some best practices for passing data through sessions in PHP?

When passing data through sessions in PHP, it is important to properly sanitize and validate the data to prevent security vulnerabilities. It is also recommended to use built-in PHP functions like `serialize()` and `unserialize()` to store and retrieve complex data structures in sessions. Additionally, setting appropriate session configuration settings, such as session cookie parameters and session timeout values, can enhance security and performance.

// Start the session
session_start();

// Store data in session after sanitizing and validating
$_SESSION['user_id'] = filter_var($_POST['user_id'], FILTER_SANITIZE_NUMBER_INT);

// Retrieve and unserialize data from session
$user_id = unserialize($_SESSION['user_id']);

// Set session configuration settings
ini_set('session.cookie_lifetime', 3600); // Session cookie lifetime of 1 hour
ini_set('session.gc_maxlifetime', 3600); // Maximum lifetime of session data in garbage collection