What is the impact of register_globals being deactivated in PHP scripts and why is it recommended to not use it?

When register_globals is deactivated in PHP scripts, it prevents variables from being automatically registered as global variables, which can improve security by reducing the risk of variable injection attacks. It is recommended to not use register_globals because it can lead to security vulnerabilities and make code harder to maintain and debug.

// Fix for register_globals being deactivated
$variable = isset($_GET['variable']) ? $_GET['variable'] : '';