Factorial Program in PHP

The factorial of number n is multiplying given integer with the sequence of its descending positive integers. we denoted the factorial of a number n by n! in mathematics. Here I am writing factorial program in PHP..

Example :-

5! = 5*4*3*2*1 = 120  

7! = 7*6*5*4*3*2*1 = 5040  

Here are writing the PHP program to find a factorial of a number.

<?php
function factorial($number){
    $factorial = 1;
    for($x=$number;$x>=1;$x--){
        $factorial = $factorial*$x;
    }
    return $factorial;
}

echo 'factorial is='.factorial(11);
?>