How can error_reporting be used to troubleshoot issues with including external PHP files?

When including external PHP files, issues can arise if the file being included contains errors. To troubleshoot these issues, you can set the error_reporting level to display all errors, warnings, and notices. This will help identify any syntax errors or other issues within the external file.

// Set error reporting to display all errors
error_reporting(E_ALL);

// Include external PHP file
include 'external_file.php';