What are the best practices for implementing user identification in PHP projects to prevent multiple or fake votes?

To prevent multiple or fake votes in PHP projects, it is essential to implement user identification. One common approach is to require users to log in or create an account before allowing them to vote. This way, each user is uniquely identified, and their vote can be tracked and validated. Additionally, using techniques like session management and IP address tracking can help further prevent fraudulent voting.

session_start();

// Check if user is logged in
if(isset($_SESSION['user_id'])) {
    // Allow user to vote
    // Your voting logic here
} else {
    // Redirect user to login page
    header("Location: login.php");
    exit();
}