Example: Harshad Number Checker in Java

// Harshad Number Checker
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 user input
        Scanner scanner = new Scanner(System.in);

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

        // Step 3: Store the original number for the divisibility check
        int originalNumber = number;
        int sumOfDigits = 0;

        // Step 4: Calculate the sum of digits
        // Use a while loop to extract digits until the number becomes 0
        while (number > 0) {
            int digit = number % 10; // Get the last digit
            sumOfDigits += digit;    // Add the digit to the sum
            number /= 10;            // Remove the last digit
        }

        // Step 5: Check if the original number is divisible by the sum of its digits
        if (sumOfDigits != 0 && originalNumber % sumOfDigits == 0) {
            System.out.println(originalNumber + " is a Harshad number.");
        } else {
            System.out.println(originalNumber + " is not a Harshad number.");
        }

        // Step 6: Close the scanner
        scanner.close();
    }
}