One Loop works perfectly and the next identical Loop fails

Question

The first loop in the second method works perfectly. when the user inputs characters instead of numbers the InputMismatchException is caught and the user is prompted to re-enter numbers only in order to continue. The second loop fails: If characters are entered for the next question, the InputMismatchException is caught and "...please try again" is displayed but then the program continues on without forcing the user to re-enter numbers. Is it possible to have more than 1 do/while, try/catch for an InputMismatchException within 1 method? I have no idea what I am doing wrong. I think I am right in theory but obviously not! How can I fix this without separating into different methods (because then my method for calculations won't work)?

           {
             Scanner input = new Scanner( System.in );
             boolean continueLoop = true;


              do{
                System.out.print("\nPlease enter weight");
                   try{

                      stone = input.nextInt();

                         while (...)
                         {
                         System.out.print("...");
                         stone = input.nextInt();
                         }
                         continueLoop = false;
                      }
                      catch ( InputMismatchException inputMismatchException)
                      {
                      System.err.printf( "\nException: %s\n", 
                      inputMismatchException );
                      input.nextLine();
                      System.out.println("...Please try again.\n" );
                      }


                 }while ( continueLoop ); 

               do{
                 System.out.print("...");
                    try{

                       pounds = input.nextDouble();


                          while (...)
                          {
                          System.out.print("...");
                          pounds = input.nextDouble();
                          }
                          continueLoop = false; 
                       }
                    catch ( InputMismatchException inputMismatchException)
                        {
                        System.err.printf( "\nException: %s\n", 
                        inputMismatchException );
                        input.nextLine();
                        System.out.println("..." );
                        }

                 }while ( continueLoop ); //code continues more methods...

When the first loop starts, `continueLoop` is true because that’s how it’s initialized. But when the second loop starts, `continueLoop` is false, because that was what caused the first loop to terminate. — VGR, Oct 23 '19 at 02:29
You need to reset the `continueLoop ` value to `true` before the subsequent loops — Scary Wombat, Oct 23 '19 at 02:30
Also, that `input.nextDouble();` inside the second `catch` is going to burn you bad. It should probably be `input.nextLine();` like the other one, or just be omitted altogether. — Dawood ibn Kareem, Oct 23 '19 at 02:31
I tried to reset boolean continueLoop = true; after the first loop and now its giving me an error relating to my main method which also has boolean continueLoop = true;. It says its already been defined in main. I've edited the code above to include my main method. This is so confusing to me. (I'm new to Java obviously) — Julie Cohen, Oct 23 '19 at 03:09

score 0 · Answer 1 · answered Oct 23 '19 at 04:35

Thanks to quick responses from VGR, Scary Wombat and Dawood ibn Kareem I now understand the solution. I reset 'boolean continueLoop = true' before the next loop but got an error. After more research (which the responses put me on the right path to) I finally figured out that I reset by entering 'continueLoop = true'!! Big problem solved and a lot learned. I spent so much time on this! I hate java. but I love Java.

One Loop works perfectly and the next identical Loop fails

1 Answers1