Php Validate international phone number using regex

function validatePhoneNumber($phoneNumber) {
  $regex = '/^\+?[0-9]{1,3}\s?\(?[0-9]{3}\)?[-\s]?[0-9]{3}[-\s]?[0-9]{4}$/';
  if (preg_match($regex, $phoneNumber)) {
    return true;
  } else {
    return false;
  }
}

//example
$result = validatePhoneNumber('+1 (555) 555-5555');

//output
echo $result; //true