This is another School / College fun program which is mostly been used in School lab to teach the basics of PHP such as if condition, for loop, multiplication, etc.,

**So what is factorial? (if you don’t know already)**

Multiplying given integer with the sequence of descending positive integers.

For example, The value of **5!** is **120.
**which is,

**5**x

**4**x

**3**x

**2**x

**1 = 120**

So, In this tutorial you are going to see you how to write a PHP program to find the **n! **using for loops!

See the program here,

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<html> <body> <title>Factorial Program in PHP</title> <!-- form post method --> <form action="" method="post"> <label>Enter Number to calculate Factorial</label> <input type="text" name="number" size="2" /> </form> </body> </html> <?php //check for post value if there then allow inside if($_POST){ $fact = 1; //get the value from input text box 'number' $number = $_POST['number']; echo "Factorial of $number:<br><br>"; //loop till the iterator $i equals to $number for ($i = 1; $i <= $number; $i++){ //formula to calculate factorial is to //multiply the iterator $i value with $fact value. $fact = $fact * $i; //print $fact to show the factorial pyramid //or put this line out of this 'for loop' to show only the total value print $fact . "<br>"; } } ?> |

Read the comments in the program to understand how it is working.

I have also given an Online demo of this above PHP factorial program, see it here:

**Enjoy the day!**

Superb

hello why are you using same variable in $fact

this my code

$facts=”1″;

for ($i = 1; $i <= $num; $i++){

$fact = $facts * $i;

}

echo $fact . "”;

when i change it it’s not work explain it

Anurag,

You are using $fact instead of $facts

Missing ‘s’ in variable.