Program 19 - CSU1128 - CSE 2026 - Shoolini University

Program to print the sum of the digits a user enters. 370 = 3 + 7 + 0 = 10

Explanation

The program calculates and prints the sum of the digits 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 four integer variables d, m, j, and o are declared. Variable m is initialized to 0 to store the sum of the digits, and o is used to store the original number.

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 for which they want to calculate the sum of its digits. The input is read using scanf("%d", &d);. The value of d is stored in another variable o for later use.

Sum of Digits Calculation

The program calculates the sum of the digits of the entered number using a while loop:

while (d > 0): Continuously checks if d is greater than 0.
j = d % 10;: Extracts the last digit of d.
m += j;: Adds the extracted digit j to the sum m.
d /= 10;: Removes the last digit from d.

Program End

The program prints the sum of the digits stored in m and the original number stored in o. It ends with printf("\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()
{
    int d, m = 0, j, o;
    printf("\n\n Program to print the sum of the digits a user enters. 370 = 3 + 7 + 0 = 10 \n\n");

    printf("Enter a number for which you want to calculate the sum of its digits (Example: 211290) - and press enter: ");
    scanf("%d", &d);
    o = d;

    while (d > 0)
    {
        j = d % 10;
        m += j;
        d /= 10;
    }

    printf("\nSum of digits of the entered number %d is %d.", o, m);
    printf("\n");
    return 0;
}

Output

Program to print the sum of the digits a user enters. 370 = 3 + 7 + 0 = 10

Enter a number for which you want to calculate the sum of its digits (Example: 211290) - and press enter: 6643
Sum of digits of the entered number 6643 is 19.