Example: Binary to Octal Converter in Java

// Binary to Octal Converter
import java.util.Scanner;

// Main class containing the entry point of the program
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        // Step 1: Get binary input from the user
        System.out.print("Enter a binary number: ");
        String binaryString = scanner.nextLine();

        // Step 2: Convert binary string to decimal
        long decimalNumber = 0;
        long power = 0;
        for (int i = binaryString.length() - 1; i >= 0; i--) {
            int digit = Character.getNumericValue(binaryString.charAt(i));
            if (digit == 1) {
                decimalNumber += (long) Math.pow(2, power);
            } else if (digit != 0) {
                System.out.println("Invalid binary input. Please enter only 0s and 1s.");
                scanner.close();
                return;
            }
            power++;
        }

        // Step 3: Convert decimal to octal
        String octalString = "";
        if (decimalNumber == 0) {
            octalString = "0";
        } else {
            while (decimalNumber > 0) {
                int remainder = (int) (decimalNumber % 8);
                octalString = remainder + octalString;
                decimalNumber /= 8;
            }
        }

        // Step 4: Display the result
        System.out.println("Octal equivalent: " + octalString);

        scanner.close();
    }
}