Example: Sum of Digits using String Conversion in Java

// Sum of Digits using String Conversion
import java.util.Scanner;

// Main class containing the entry point of the program
public class Main {
    public static void main(String[] args) {
        // Step 1: Create a Scanner object to read input
        Scanner scanner = new Scanner(System.in);

        // Step 2: Prompt the user to enter a number
        System.out.print("Enter a number: ");
        int number = scanner.nextInt();

        // Step 3: Convert the integer to a string
        String numberStr = String.valueOf(number);

        // Step 4: Initialize sum to 0
        int sum = 0;

        // Step 5: Iterate through each character of the string
        for (int i = 0; i < numberStr.length(); i++) {
            // Step 5a: Get the character at the current index
            char digitChar = numberStr.charAt(i);

            // Step 5b: Convert the character digit back to an integer and add to sum
            // Character.getNumericValue() handles conversion correctly for digits '0'-'9'
            sum += Character.getNumericValue(digitChar);
        }

        // Step 6: Print the sum of digits
        System.out.println("Sum of digits for " + number + " is: " + sum);

        // Step 7: Close the scanner
        scanner.close();
    }
}