Example: Sum of Digits (Recursive) in C++

C
C++
C#
Java
Python
PHP
// Sum of Digits (Recursive)
#include <iostream>
using namespace std;

// Function to calculate the sum of digits recursively
int sumOfDigitsRecursive(int n) {
    // Step 1: Base Case - If the number is 0, the sum is 0
    if (n == 0) {
        return 0;
    }
    // Step 2: Recursive Step - Add the last digit to the sum of remaining digits
    else {
        return (n % 10) + sumOfDigitsRecursive(n / 10);
    }
}

int main() {
    int number;

    // Step 3: Prompt the user to enter a number
    cout << "Enter a number: ";
    cin >> number;

    // Step 4: Call the recursive function
    int sum = sumOfDigitsRecursive(number);

    // Step 5: Display the result
    cout << "The sum of digits of " << number << " is: " << sum << endl;

    return 0;
}