Sum of Digits of a Number in C using While loop | For | Function | Recursion | Without loop

Sum of digits of a number in C using while loop.

In this article, you will learn how to find the sum of digits of a number in C using while loop.

 

Example

 

You should have knowledge of the following topics in c programming to understand this program:

• C main() function
• C printf() function
• C while loop
• C for loop
• C Functions
• C Recursion

 

Sum of Digits of a Number

 

In this article, we solve this problem in six methods:

1. Using the while loop
2. Using the for loop
3. Without using loop
4. Using the function
5. Using the recursion
6. Using the do-while loop

Source Code

// Sum of Digits of a Number in C using While loop
#include <stdio.h>

int main() {
    int x, sum = 0, m;
    
    printf ("Enter the integer number::\n");
    scanf ("%d", &x);
    
    printf ("The sum of %d digits is = ", x);
    while (x > 0) {
        m = x%10;    
        sum = sum+m;    
        x = x/10;    
    }
    
    printf ("%d\n", sum);
    return 0;
}

Run Program

Output

---

Sum of Digits of a Number in C using For loop

// Sum of Digits of a Number in C using For loop
#include <stdio.h>

int main() {
    int x, sum = 0, m;
    
    printf ("Enter the integer number::\n");
    scanf ("%d", &x);
    
    printf ("The sum of %d digits is = ", x);
    for (int i = x; i > 0; i = i/10) {
        m = i%10; 
        sum = sum+m;
    }
    
    printf ("%d\n", sum);
    return 0;
}

Run Program

 

Explanation

In this given program, we have taken input 3579 from the user then divide digits of this number and add them to each other to solve this calculation: 3 + 5 + 7 + 9 = 24.

Then this will return the 24 the final output of the above calculation.

---

Sum of Digits of a Number in C Without loop

// Sum of Digits of a Number in C Without loop
#include <stdio.h>

int main() {
    int x, sum = 0;
    
    printf ("Enter the 3 digit's integer number::\n");
    scanf ("%d", &x);
    
    printf ("The sum of %d digits is = ", x);
    sum = (x % 10) + ((x / 10) % 10) + (x / 100);
    
    printf ("%d\n", sum);
    return 0;
}

Run Program

Output

---

Sum of Digits of a Number in C using Function

// Sum of Digits of a Number in C using Function
#include <stdio.h>

// This function will make sum of digits of number itself
void DigitSum(int x) {
    int sum = 0, m;

    printf ("The sum of %d digits is = ", x);
    while (x > 0) {
        m = x%10;    
        sum = sum+m;    
        x = x/10;    
    }
    
    printf ("%d\n", sum);
}

// It's the driver function
int main() {
    int x;
    
    printf ("Enter the integer number::\n");
    scanf ("%d", &x);
    
    DigitSum(x);
    return 0;
}

Run Program

Output

---

Sum of Digits of a Number in C using Recursion

// Sum of Digits of a Number in C using Recursion
#include <stdio.h>

// This function will make sum of digits of number itself
// Using the recursion
int DigitSum(int x) {
    if (x == 0)
        return 0;
    return (x % 10 + DigitSum(x / 10));
}

// It's the driver function
int main() {
    int x;
    
    printf ("Enter the integer number::\n");
    scanf ("%d", &x);
    
    printf ("The sum of %d digits is = ", x);
    printf("%d\n", DigitSum(x));
    return 0;
}

Run Program

---

Sum of Digits of a Number in C using Do While loop

// Sum of Digits of a Number in C using Do While loop
#include <stdio.h>

int main() {
    int x, sum = 0, m;
    
    printf ("Enter the integer number::\n");
    scanf ("%d", &x);
    
    printf ("The sum of %d digits is = ", x);
    do {
        m = x%10;    
        sum = sum+m;    
        x = x/10;    
    } while (x > 0);
    
    printf ("%d\n", sum);
    return 0;
}

Run Program

Output

 

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