Q. PHP Program to Find Factorial of a Given Number.

Here you will find an algorithm and program in PHP to find factorial of a number. First let us understand what factorial means.

Explanation : The factorial of a number is the product of all the integers from 1 to that number.

For Example : Factorial of 5 is 120 i.e. 5*4*3*2*1

START
step 1 : Read the number n
step 2 : [Initialize]
         i=1, fact=1
step 3 : Repeat step 4 through 6 until i=n
step 4 : fact=fact*i
step 5 : i=i+1
step 6 : Print fact
STOP

PHP Program to Find Factorial of a Number

$num = 7;  
$fact = 1;  
for ($x=$num; $x>=1; $x--)   
{  
  $fact = $fact * $x;  
}  
echo "Factorial of $num = $fact";  

Output

Factorial of 7 = 5040