# How to write a C program to find factorial of a given number

Factorial of a number: A factorial of a number n, denoted by n!, is the product of all positive integers less than or equal to n

example: factorial of 4 is : 4! = 4x3x2x1 = 24 . similarly factorial of 3 is: 3!=3x2x1=6 and factorial of 6 is: 6! = 6x5x4x3x2x1 = 720

Factorial of a number in c language can be calculated using for loops for and while

and also using recursion technique

1>Write a C program to find factorial of a given number using while loop

Write a program to print factorial of a given number using c programming

#include<stdio.h>

void main()

{

int num, c , factorial; // c is count variable

printf(“To find factorial of a given number \n”);

printf(“Enter the number :”);

scanf (“%d \n”, &num);

c =1;

factorial=1;

while ( num > 1)

{

c++ ;

factorial=factorial*c;

num= num-1;

}

printf(“The factorial of the entered number is:%d”, factorial);

}

OUTPUT:

To find factorial of a given number

Enter the number : 5

The factorial of the entered number is 120

2>WAP to calculate factorial of a given number using for loop using c programming

Write a program to find factorial of a given number using for loop

#include<stdio.h>

void main()

{

int c , factorial=1, i; // c is number

printf(“To calculate factorial of a given number \n”);

printf(“Enter the number :”);

scanf (“%d \n”, &c);

for(i=2;i<=c;i++)

{

factorrial=factorial*i;

}

printf(“The factorial of the number %d is:%d”, c , factorial);

}

OUTPUT:

To calculate factorial of a given number

Enter the number : 5

The factorial of number 5 is 120

3>Write a C program to calculate factorial of a given number using factorial function

WAP to find factorial of a given number using factorial function using c programming

#include<stdio.h>

void main()

{

int n;

printf(“To show factorial of a given number \n”);

printf(“Enter the number whose factorial is to be calculated:”);

scanf (“%d \n”, &n);

printf(“The factorial of the entered number is:”);

int findfactorial(n);

}

findfactorial(int c )

{

int factorial=1, i;

for(i=2;i<=c;i++)

{

factorial=factorial*i;

}

return(factorial);

}

OUTPUT:

To show factorial of a given number

Enter the number whose factorial is to be calculated: 5

The factorial of the entered number is 120