Factorial Number in PHP. Execute the program factorial number what is factorial program and how it works in php language. This script will help you to find the number is factorial or not in PHP.

<?php

$number = 4;

$fact = 1;

for ($x=$number; $x>=1; $x--)

{

$fact = $fact * $x;

}

echo "fact of $number is $fact";

?>

Output:

fact of 4 is 24

## Factorial Number in PHP

The factorial is a quantity defined for all integers larger than or equal to 0. It is denoted by an exclamation point (!). The factorial is the product of all integers less than or equal to n but greater than or equal to 1 for an integer n greater than or equal to 1. Number theorists are fascinated by the factorial.

## Why Factorial of 0 is 1

Because this data set can only be structured in one way, a zero factorial is equal to one by definition, just as 1! is equivalent to one.

## Purpose of Factorial Numbers

The mathematical definition of factorial is the operation of multiplying every natural number by all the natural numbers that are smaller than it. Finally, factorial is used to ask how many different ways you may arrange or organize a specific amount of items.

Python Program to Print Array Elements

Smallest Element in Array Python

Ascending Order Program in Python Using For Loop

Student Mark List Program in Python

Area of Triangle in Python Program

Program to Calculate Area of Square in Python

Python Program to Calculate Area of Triangle