function user_registration($user_name, $user_email, $user_pass, $address,
                           $city, $postalcode, $country, $phone, $mobilephone)

class User {

  public function setName($name) {
    $this->name = $name;
  }

  [...]

  public function register() {

    //Validate input
    if (empty($this->name))
      $this->errors[] = "ERROR, Username must not be emtpy";

    //Add the user to the database
    //Your SQL query
    return empty($this->errors);
  }

}

$user = new User();
$user->setName("Peter");
$success = $user->register();

if (!$success)
  echo "ERRORS OCCURED: ".print_r($user->errors, true);

function user_registration(array $data) {
    // work with $data['name']
    // and $data['email']
    // ...
}

user_registration(array(
    'name' => 'blah',
    'email' => 'test@example.com',
    'pass' => '123456',
    // and so on
));

function user_registration(array $user_info)
{
   // process $user_info;
}

User Data:    $user_name, $user_pass
Address Data: $address, $city, $postalcode, $country
Contact Data: $user_email, $phone, $mobilephone

function user_registration(User $user, Address $address, Contact $contact)

function user_registration(User $user)

$user = new User('johndoe', 'secretsauce');
$user->setAddress(new Address('Doe Street', 'Doe Town', 12345, 'Neverland'));
$user->setContact('jdoe@example.com', '+123 12345', '+123 54321');
user_registration($user);

user_registration(new User($credentials, $address, $contact));

$user = new User(new Credentials('johndoe', 'secretsauce'));
$user->setAddress(new Address('Doe Street', 'Doe Town', 12345, 'Neverland'));
$user->setContact(new Contact('jdoe@example.com', '+123 12345', '+123 54321'));
user_registration($user);

$user = new User($credentials);
$user->setAddress($address);
$user->setContact($contact);
$user->register();

$user = new User;
$user->setAddress($address);
$user->setContact($contact);
$user->register($credentials);

private var $name;

public function register()

$fields = array('field1', 'field2');
function register (array $values, array $keys)
{
    $data = array();
    foreach ($keys as $one)
    {
        if (isset($values[$one])) $data[$one] = $values[$one];
    }
    // or you can use array functions like array_flip and after - array intersect
}

fields=explode(",","name,surname,lastname,street,city,region,zip,country");
user_registration($fields);