How can debugging techniques in PHP, such as error logging or step-by-step execution, be utilized to troubleshoot issues like sudden script failures?

To troubleshoot sudden script failures in PHP, utilizing error logging can help identify the specific error that caused the failure. By logging errors to a file or outputting them to the browser, you can track down the issue more easily. Additionally, using step-by-step execution techniques, such as adding echo statements or using a debugger, can help pinpoint where the script is failing.

// Enable error logging
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

// Log errors to a file
ini_set('log_errors', 1);
ini_set('error_log', '/path/to/error.log');

// Step-by-step execution with echo statements
echo "Before step 1";
// Step 1 code
echo "After step 1";
// Step 2 code
echo "After step 2";
// Step 3 code
echo "After step 3";