How can PHP developers troubleshoot and debug issues with regular expressions when they are not producing the desired results, as seen in the forum thread?

Issue: PHP developers can troubleshoot and debug issues with regular expressions by using online regex testers, such as regex101.com, to test their patterns and see where they might be going wrong. They can also use functions like preg_match() and preg_replace() in PHP to test their regular expressions against sample data and see if they are producing the desired results.

// Example PHP code snippet to troubleshoot and debug regular expression issues
$pattern = '/^[0-9]{3}-[0-9]{2}-[0-9]{4}$/'; // Regular expression pattern for a social security number format
$data = '123-45-6789'; // Sample data to test against the regular expression

if (preg_match($pattern, $data)) {
    echo 'Valid social security number format';
} else {
    echo 'Invalid social security number format';
}