# Write a program to calculate and print the factorial of a number in php

Write a program to calculate and print the factorial of a 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

#### What is factorial number and how to find the 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.

#### What is the 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.