Calculate Sum of Digits of a Number in Function in C++

 #include<iostream>

using namespace std;

void sum(int n) {

    int totalSum = 0;

   

    while(n > 0) { // calculates until loop reaches n

    totalSum = totalSum + n; // adds the no. to totalSum

    n--; // decrements n to break the loop at the end

    }

    cout << totalSum << " " << endl;

}

int main(){

    sum(5);

    return 0;

}

OUTPUT-

15