Where can one find comprehensive documentation on using regular expressions in PHP for form validation?

Regular expressions are a powerful tool for validating input in PHP forms. To find comprehensive documentation on using regular expressions for form validation in PHP, one can refer to the official PHP documentation on regular expressions. This documentation provides detailed explanations, examples, and syntax for using regular expressions effectively in PHP form validation.

// Example of using regular expressions for form validation in PHP
$email = "example@example.com";

// Validate email using preg_match
if (preg_match("/^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/", $email)) {
    echo "Valid email address";
} else {
    echo "Invalid email address";
}