abstract class Tier
{
 public $Name;
 public $Fellfarbe;
 public $KrallenLaenge;
 public $AnzahlBeine;
 public function gibNamenAus()
 {
   echo "Ich heiße ".$this->name."\n";
 }
}
class Hund extends Tier
{
 public $GefangeneKatzen;
 public function gibLaut()
 {
  echo "Wau\n";
 }
}
class Katze extends Tier {
 public $GefangeneVoegel;
 public function gibLaut()
 {
   echo "Miau\n";
 }
}
class Amsel extends Tier
{
 public $GefangeneInsekten;
 public function gibLaut()
 {
  echo "Piep";
 }
}
$obj = new Katze;
$obj->gibLaut();