Example: Sum of Digits using While Loop in C++

C
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C#
Java
Python
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// Sum of Digits using While Loop
#include <iostream>
using namespace std;

int main() {
    int number;
    int sum_of_digits = 0;

    // Step 1: Prompt user for input
    cout << "Enter a positive integer: ";
    cin >> number;

    // Handle negative numbers by taking absolute value, if desired
    // if (number < 0) {
    //     number = -number;
    // }

    // Store the original number for display later
    int original_number = number;

    // Step 2: Loop until the number becomes 0
    while (number > 0) {
        // Step 2a: Get the last digit using modulo operator
        int digit = number % 10;

        // Step 2b: Add the digit to the sum
        sum_of_digits += digit;

        // Step 2c: Remove the last digit using integer division
        number /= 10;
    }

    // Step 3: Display the result
    cout << "The sum of digits of " << original_number << " is: " << sum_of_digits << endl;

    return 0;
}