C program to compute the sum of digits in a given numbers

In this tutorial, we will discuss a concept of C program to compute the sum of digits in a given numbers

In C programming language, we can use for loop ,while loop and do-while loop to compute the sum of digits in a given numbers

In this article, we are going to learn how to find the sum of digits in a given number in C language

Compute the sum of digits using loops

Compute the sum of digits in a given numbers using for loop

Program 1

#include <stdio.h>
#include <stdlib.h>

int main()
{
    long num,count,digits,sum=0;
    printf("Enter a number\n");
    scanf("%ld",&num);

for(count=num; num>0; num/=10)
{
    digits=num%10;
    sum=sum+digits;

}
printf("Given number is: %ld\n",count);

printf("\nSum of the digits %ld is = %ld\n",count,sum);
getch();
    return 0;
}

When the above code is executed, it produces the following results

Csae 1

Enter a number for find digits sum
111100
Given number is:111100

Sum of the digits  111100 is = 4

Csae 2

Enter a number for find digits sum
12345
Given number is:12345

Sum of the digits  12345 is = 15

Compute the sum of digits in a given numbers using while loop

Program 2

#include <stdio.h>
#include <stdlib.h>

int main()
{
    long num,count,digits,sum=0;
    printf("Enter a number for find sum of digits\n");
    scanf("%ld",&num);

    count=num;;
while( num>0)
{
    digits=num%10;
    sum=sum+digits;
    num/=10;

}
printf("Given number is: %ld\n",count);

printf("\nSum of the digits %ld is = %ld\n",count,sum);
getch();
    return 0;
}

When the above code is executed, it produces the following results

Case 1

Enter a number for find sum of digits
1030
Given number is:1030

Sum of the digits  1030 is = 4

Case 2

Enter a number for find digits sum
56789
Given number is:56789

Sum of the digits  56789 is = 35

Compute the sum of digits in a given numbers using do while loop

Program 3

#include <stdio.h>
#include <stdlib.h>

int main()
{
    long num,count,digits,sum=0;
    printf("Enter the number for find sum of digits\n");
    scanf("%ld",&num);

    count=num;;

do{
    digits=num%10;
    sum=sum+digits;
    num/=10;

}while( num>0);
printf("Given number is: %ld\n",count);

printf("\nSum of the digits %ld is = %ld\n",count,sum);
getch();
    return 0;
}

When the above code is executed, it produces the following results

Case 1

Enter a number for find sum of digits
11111
Given number is:11111

Sum of the digits  11111 is = 5

Case 2

Enter a number for find digits sum
76543
Given number is:76543

Sum of the digits  76543 is = 25

Methods

Declare the variable num,count and digits as long type.
Declare and initialize variable sum to Zero.
Receive input from the user for the value to find the sum of digits and to store the variable num.
Using a loop (for loop , while loop, do-while loop) get each digit of the number and add it to the to a variable to find the sum.
Display the sum of the digits of the number.