PHP 코드로 간단한 팩토리 패턴 구현

//家禽类 abstract class Fowl { abstract public function eat();//吃方法 }

//牛类 class Cattle extends Fowl { public function eat() { echo "我是牛，我吃草"; } } //鸭类 class Duck extends Fowl { public function eat() { echo "我是鸭，我吃鱼"; } } //羊类 class Sheep extends Fowl { public function eat() { echo "我是羊，我吃草"; } }