How does the register_shutdown_function('session_write_close') impact session handling in PHP and what alternative parameters can be used?

The `register_shutdown_function('session_write_close')` call in PHP ensures that the session data is written and closed at the end of the script execution, which helps prevent data loss and conflicts in session handling. An alternative parameter that can be used with `register_shutdown_function` for session handling is a custom function that performs additional tasks before closing the session, such as logging or cleanup operations.

// Register a custom function for session handling
function custom_session_cleanup() {
    // Perform additional tasks before closing the session
    session_write_close();
    // Additional cleanup operations
}

// Register the custom function for shutdown handling
register_shutdown_function('custom_session_cleanup');