Why is it recommended not to directly modify the $_GET superglobal variable in PHP?

Modifying the $_GET superglobal variable directly in PHP is not recommended because it can introduce security vulnerabilities such as injection attacks. To avoid this issue, it is recommended to sanitize and validate user input before using it in the code. This can be done by creating a copy of the $_GET array and manipulating the copy instead of the original superglobal variable.

// Sanitize and validate user input from $_GET
$safe_get = filter_input_array(INPUT_GET, FILTER_SANITIZE_STRING);

// Now you can safely use $safe_get in your code