How can the use of register_globals in PHP.ini impact the functionality of PHP scripts and how can it be managed effectively?

Using register_globals in PHP.ini can impact the functionality of PHP scripts by making variables global by default, which can lead to security vulnerabilities and unexpected behavior. To manage this effectively, it is recommended to disable register_globals in the PHP configuration file and refactor the code to use superglobal arrays like $_GET, $_POST, and $_SESSION to access variables.

// Disable register_globals in PHP configuration file (php.ini)
register_globals = Off;