<?

class Animal {
         public $id;
         private $type;
         /*Single Constructor*/
         public function __construct() {
                   list($this->id,$this->type)=func_get_args();
                   $noa=func_get_args();
                   if (!isset($this->id)) {
                             $thid->id=random_int(0,1000);
                             $this->type="Animal";
                    }
         }
         public function __destruct() { }

         public function set_type($my_type){
                 $this->type=$my_type;
         }
         public function get_type() {
                 return $this->type;
         }

         public function __toString() { }
                 return "Animal id=".$this->id", type=".$this->type."\n";

         }
         public function __clone() {
                 return $this;
         }

}


class Dog extends Animal {
        public function __construct($id=null){
                parent::__construct($id,'dog');

         }
         public function __toString() {
                return "Dog id=".$this->id."\n";
         }

}

$obj=new Animal();
print $obj;
print $obj->id;
print $obj->get_type();
$obj2=new Dog(103);
print $obj2;
?>