abstract class using PHP 5

test-abstract-class.php

<?php 
abstract class Ayam{
  public abstract function berjenisKelamin();
}

class AyamJantan extends Ayam{
	public function berjenisKelamin(){
		echo "jantan";
	}
}

class AyamBetina extends Ayam{
	public function berjenisKelamin(){
		echo "betina";
	}
}

$ayamjantan = new AyamJantan();
$ayambetina = new AyamBetina();

$ayam = $ayamjantan;
echo $ayam->berjenisKelamin();

$ayam = $ayambetina;
echo $ayam->berjenisKelamin();
?>