How can one update or modify existing PHP code that uses session_register() to comply with newer PHP versions?

The session_register() function is deprecated in newer PHP versions and should not be used. To update existing PHP code that uses session_register(), you should replace it with the $_SESSION superglobal array to store session variables. This ensures compatibility with newer PHP versions and maintains the functionality of session management in your code.

// Replace session_register() with $_SESSION superglobal array

// Before
session_start();
$var = "value";
session_register('var');

// After
session_start();
$var = "value";
$_SESSION['var'] = $var;