How can the separation of form processing logic into a separate file impact the visibility of error messages and debugging information in PHP?

Separating form processing logic into a separate file can impact the visibility of error messages and debugging information in PHP because errors may occur in the processing file, but the error messages might not be displayed to the user on the form page. To solve this issue, you can use error handling techniques, such as setting error reporting levels and displaying error messages in the processing file.

// Separate form processing logic into a separate file
// processing.php

// Set error reporting level to display errors
error_reporting(E_ALL);
ini_set('display_errors', 1);

// Your form processing code here
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    // Process form data
}