Write a program to calculate the factorial for given number using function.

Dr. A.P.J. Abdul Kalam Technical University, Lucknow

KCS151 / KCS251 Programming for Problem Solving - Using C Language

Lab Exercises

17. Write a program to calculate the factorial for the given number using a function.

/*

 File: Prgrm17.c

 Author: Aditya Saini

 Date: Jan 17, 2021

 Description: Program to calculate the factorial for the given number using a function.

*/

#include <stdio.h>

int factorial (int);

int main (void)

{

     int num;

     int fact;

     //Input number

     printf ("Input number: ");

     scanf ("%d", &num);

     //Function call

     fact = factorial (num);

     //Print result

     if (fact > 0)

     {

          printf ("Factorial: %d", fact);

     }

     return 0;

};

int factorial (int num)

{

     int fact;

     int i;

     //Calculate factorial

     fact = 1;

     if (num >= 0)

     {

          for (i = 1; i <= num; i++)

               fact = fact * i;

          return fact;

     }

     else

     {

          printf ("Error! Negative number");

          return -1;

     }

};

Output

Input number: 5

Factorial: 120