Sum the Digits of a Given Number in C

The calculation of the sum of the digits of a number in a single statement means that only one line of code will be doing the addition operation. The addition operation should not extend more than one statement.

In this article, we have a number and our task is to calculate the sum of the digits of the number in a single statement in c. Here is a list of approaches:

• Using for Loop
• Using Recursive Function

Using for Loop

This approach uses a for loop to calculate the digit sum in one statement. The for loop continues till num reaches 0.

• The num % 10 finds the last digit of the number.
• Then we add the last digit each time and store it in the variable sum.
• Then, we remove the last digit of the number by dividing it by 10.

Example

Here is an example of implementing the above-mentioned steps to add digits of a number in a single statement using a for loop:

#include <stdio.h>
int main() {
    int num = 534, sum = 0;
    for(; num; sum += num % 10, num /= 10);
    printf("Sum of digits of the number is: %d", sum);
    return 0;
}

The output of the above code is given below:

Sum of digits of the number is: 12

Using Recursive Function

You can use a recursive function to calculate the sum of digits of the number in a single statement.

• The num % 10 is used for finding the last digit of the number.
• The sum() function is recursively called to remove the last digit of the number.
• Then, we add all the last digits of the number from step 1 with the digit received after step 2 at the end of the recursion.

Example

Here is an example of a recursive approach to get the sum of digits of number in a single statement:

#include <stdio.h>
int sum(int num) {
    return num ? (num % 10 + sum(num / 10)) : 0;
}
int main() {
    int num = 534;
    printf("Sum of digits of the number is: %d", sum(num));
    return 0;
}

The output of the above code is given below:

Sum of digits of the number is: 12