PHP Sessions

Starting a Session

session_start();
$_SESSION["user_id"] = 123;
$_SESSION["username"] = "alice";

Accessing Session Data

session_start();
if (isset($_SESSION["username"])) {
    echo "Welcome back, " . $_SESSION["username"];
}

Destroying a Session

session_start();
session_destroy();  // End session

Security Best Practices

• Regenerate session ID after login: session_regenerate_id()
• Use HTTPS in production
• Set appropriate session timeout

---