How can developers ensure that their websites are secure when implementing cookie functionality in PHP?

Developers can ensure that their websites are secure when implementing cookie functionality in PHP by setting the 'secure' flag to true when creating cookies. This flag ensures that cookies are only sent over HTTPS connections, making them less vulnerable to attacks like eavesdropping. Additionally, developers should also set the 'httponly' flag to true to prevent cookies from being accessed through client-side scripts, further enhancing security.

// Set a secure cookie with the 'secure' and 'httponly' flags
setcookie('cookie_name', 'cookie_value', time() + 3600, '/', '', true, true);