Program 25 - CSU1128 - CSE 2026 - Shoolini University

Program to print the factorial of the number entered by the user. Example 3 = 3 x 2 x 1 = 3

Explanation

The program calculates and prints the factorial of a number entered by the user.

Header

The code begins with including the standard input-output header file using #include <stdio.h>.

Variable Declaration

The main() function is defined, and three variables are declared:

long int d: Stores the number entered by the user.
long int m: Used as a loop counter.
long int j: Initialized to 1 and used to store the factorial result.

Program Description

The program prints a description message for the user to understand its functionality.

User Input

The user is prompted to enter a number up to 25 for which they want to calculate the factorial. The input is read using scanf("%ld", &d);.

Factorial Calculation

The program calculates the factorial of the entered number using a for loop:

for (m = 1; m <= d; m++): Loops through each number from 1 to d.
j *= m;: Multiplies j by the current value of m and stores the result in j.

Output Result

The program prints the factorial of the entered number stored in j.

Program End

The program ends with printf("\n\n"); to print a new line and return 0; to indicate successful execution.

Code

                    
/*
 * -----------------------------------------------------------
 * Logic Building with Computer Programming (CSU1128)
 * Instructor: Dr. Pankaj Vaidya | Author: Divya Mohan
 * 
 * This code is a part of the educational initiative by dmj.one
 * with aim of empowering and inspiring learners in the field of
 * Computer Science and Engineering through the respective courses.
 * 
 * (c) 2022, Divya Mohan for dmj.one. All rights reserved.
 * -----------------------------------------------------------
 */

#include <stdio.h>
int main()
{
    long int d, m, j = 1;
    printf("\n\n Program to print the factorial of the number entered by the user. Example 3 = 3 x 2 x 1 = 3 \n\n");

    printf("Enter a number till 25 for which you want to print its factorial (Example: 21) - and press enter: ");
    scanf("%ld", &d);
    printf("\n Factorial of the entered number %ld is: ", d);

    for (m = 1; m <= d; m++)
    {
        j *= m;
    }
    printf(" %ld", j);
    printf("\n\n");
    return 0;
}

Output

Program to print the factorial of the number entered by the user. Example 3 = 3 x 2 x 1 = 3

Enter a number till 25 for which you want to print its factorial (Example: 21) - and press enter: 6
Factorial of the entered number 6 is: 720