PHP recursive function to find factorial

 function demo($a)
 {
 if($a > 1)
 {
 $r=$a*demo($a-1);
 }else
 {
 $r=$a;
 }

 return $r;
 }

 $a=6;
 echo $a."The value of the factorial".demo($a);
?>

The display result of php recursive function to find factorial: