Question

1. Ask the user to enter the number in binary format.

2. Check to see that the number entered is actually in binary format (starts with a '1' and only has '0's and '1's).

- If the user input is something that is not correct, then ask the user to re-enter the number. Make sure you respond appropriately so the user has some idea of what went wrong.

Answer 1

/***********************CheckBinary.java*****************/

import java.util.Scanner;

public class CheckBinary {

   public static void main(String[] args) {

       Scanner scan = new Scanner(System.in);

       System.out.print("Enter Binary String: ");
       String input = scan.nextLine();

       boolean status = false;

       while (!status) {

           for (int i = 0; i < input.length(); i++) {

               if (input.charAt(0) == '1' && (input.charAt(i) == '0' || input.charAt(i) == '1')) {

                   status = true;
               }

               if (!status) {

                   System.out.print("Enter correct binary number: ");
                   input = scan.nextLine();
               }
           }
       }
      
       System.out.println("Binary number is: "+input);
       scan.close();

   }
}
/**************output**********************/

Enter Binary String: 01111
Enter correct binary number: 1001010101010
Binary number is: 1001010101010

Please let me know if you have any doubt or modify the answer, Thanks:)