How can the problem of register globals affecting form data processing in PHP be addressed effectively?

Register globals in PHP can pose a security risk by allowing external data to overwrite global variables, including form data. To address this issue effectively, you should disable register globals in your PHP configuration settings or use the $_POST or $_GET superglobals to access form data securely.

// Disable register globals in PHP configuration settings
// OR use $_POST or $_GET superglobals to access form data securely

// Example using $_POST superglobal
$username = isset($_POST['username']) ? $_POST['username'] : '';
$email = isset($_POST['email']) ? $_POST['email'] : '';