'"%value" is not a valid Czech phone number!
Czech phone numbers should contain only numbers and spaces be like 999 999 999 with an optional prefix of "+420" or "00420".', ); } /** * Verifies that $phonenumber is a valid nine-digit Czech phone number * * @param string $phonenumber * @return boolean Returns boolean FALSE if the phone number is not valid. */ function valid_cs_phone_number($phonenumber) { $phonenumber = trim($phonenumber); // define regular expression $regex = '/^((?:\+|00)420)? ?(\d{3}) ?(\d{3}) ?(\d{3})$/'; // return true if valid, false otherwise return (bool) preg_match($regex, $phonenumber); } /** * Convert a valid Czech phone number into standard (+420) 999 999 999 format * * @param $phonenumber must be a valid nine-digit number (with optional international prefix) * */ function format_cs_phone_number($phonenumber, $field) { // define regular expression $regex = '/^((?:\+|00)420)? ?(\d{3}) ?(\d{3}) ?(\d{3})$/'; // get digits of phone number preg_match($regex, $phonenumber, $matches); if ($field['phone_country_code']) { $phonenumber = '+420' . ' ' . $matches[2] .' '. $matches[3] .' '. $matches[4]; } else { $phonenumber = $matches[2] .' '. $matches[3] .' '. $matches[4]; } return $phonenumber; }