fiscalCode.php

<?php

function validateFiscalCode($fiscalCode) {
    $regex = "/^[A-Z]{6}\d{2}[A-G]\d{2}[A-Z]\d{3}[A-Z]$/";
    return preg_match($regex, trim($fiscalCode, " "));
}

function birthYear($fiscalCode) {
    $birthYear = substr($fiscalCode, 6, 2);
    if ($birthYear <= "99" && $birthYear > "25")
        return intval("19" . $birthYear);
    return intval("20" . $birthYear);
}

function isAdult($fiscalCode) { 
    return date("Y") - birthYear($fiscalCode) >= 18;
}

?>