Topic awaiting preservation: class, inheritance, polymorphism ect

<?
class Animal{
	function Animal($colour){
		$this->colour = $colour;
	}
	function report(){
		return "This ".$this->colour." ".get_class($this)." has ".$this->legs." legs.<br>";
	}
}
	
class Cat extends Animal{
	var $legs = 4;
}
class Panther extends Cat{
 var $colour = "black";
 function Panther(){}
}
class Snake extends Animal{
	var $legs = 0;
}
$tiddles = new Cat();
$tiddles->legs--;
$moggy = new Panther();
$hissy = new Snake("brown");
echo $tiddles->report();
echo $moggy->report();
echo $hissy->report();
?>

class Animal{
	
       function Animal() {}
        
       function Animal($colour){
		$this->colour = $colour;
	}
	function report(){
		return "This ".$this->colour." ".get_class($this)." has ".$this->legs." legs.<br>";
	}
}