Do-while problem, or other problem?

[pakupakuman]

Hello -

Learning Java, I'm converting a simple guess-the-number game from C++ to Java. As the code stands, the basics are working. You have three tries to guess a number, and the computer will let you know if your guess is too low or too high.

i think that the problem is in the "play again y/n" part of the program. regardless of your selection, it will continue to play, and the "number of attempts" counter doesn't reset.

Here's the code:

/*
 * Filename: 	GuessTheNumber.java
 * Created: 	9-28-2012 by MH
 *
 * Purpose: 	Conversion of Guess the Number Game from C++ to Java
 *
 */

import javax.swing.*;     // GUI
import java.util.Random;  // Randomizer

public class GuessTheNumber
{

   //main method
   public static void main ( String[] args )
   {

      //declare and initialize variables
      int compnum, yournum, tries;
      String selectyn, openingMessage, instructionMessage, attemptMessage, yournumString, windowMessage;

      //display opening messages
      openingMessage  = "Find and defuse the bomb!";
      JOptionPane.showMessageDialog( null, openingMessage );
      selectyn = "y";

      // game routine
      do
      {
          instructionMessage  = "Guess a number from 1 to 10.  You have three tries.";
          JOptionPane.showMessageDialog( null, instructionMessage );


          Random rand = new Random();        // random object
          compnum = rand.nextInt(10)+1;  // random number from 1 to 10

          tries = 0;
	  while (tries < 4)
	  {
              tries++;

              // get required input using dialog boxes
              attemptMessage = "Attempt number " + tries + ":";
              yournumString = JOptionPane.showInputDialog ( attemptMessage );
              yournum = Integer.parseInt( yournumString );//convert string to integer

	      // determine if numbers match
	      if (compnum == yournum)
              {
                  //congratulations, play again?
		  windowMessage = "Conrgatulations!!! \n";
                  JOptionPane.showMessageDialog( null, windowMessage );
		  PlayAgain();
              }
	      else
		 {
		 if ((compnum > yournum) && (tries < 3))
		    {
                       windowMessage = "Uh oh.  The secret number is higher. \n";
                       JOptionPane.showMessageDialog( null, windowMessage );

                    }
                    else
                       {
                          if ((compnum < yournum) && (tries < 3))
                             {
                                 windowMessage = "Uh oh.  The secret number is lower. \n";
                                 JOptionPane.showMessageDialog( null, windowMessage );
                             }
                       }
                 }

              if ((tries ==3) && (compnum != yournum))
                 {
                       windowMessage = "KABOOOM!!!  The secret number was " + compnum + ". \n\n";
                       JOptionPane.showMessageDialog( null, windowMessage );
		       PlayAgain();
                 }
           }

   }  // end do
   while (selectyn == "y");
   System.exit(0);
} // end main


public static void PlayAgain()
   {
      int tries;
      String selectyn, selectynMessage;
      selectynMessage = "Would you like to play again (y/n)?";
      selectyn = JOptionPane.showInputDialog( selectynMessage );
      if (selectyn == "n")
         {
         System.exit(0);         
         }
            else
               {
                  tries = 0;
               }
   }
            
} // end class

Can somebody please take a stabat it and tell me where I'm messing it up? I know it's got to be something simple, but I can't see it. Thanks!

[DarrylBurke]

Don't use the == comparison operator to compare Strings or any Objects. Use the .equals(...) method.

db

[pakupakuman]

Thanks for that tip! That part is now working.

Edit was as follows:

public static void PlayAgain()
   {
      int tries;
      String ynNoSelected = "n";
      String selectyn, selectynMessage;
      selectynMessage = "Would you like to play again (y/n)?";
      selectyn = JOptionPane.showInputDialog( selectynMessage );
      if (selectyn.equals(ynNoSelected))
         {
         System.exit(0);         
         }
            else
               {
                  tries = 0;
               }
   }

I added a string so equals could compare the input to the stored string.

Now I'll work on the number of attempts, which is still going over 3.

[Fubarable]

I don't see a loop in your code above. If you're still stuck, please post the relevant code.

[pakupakuman]

Hello -

Still stuck here. The "play again" works if you wish to exit, but the number of tries does not immediately reset (keeps on going).

Here's what I have right now:

/*
 * Filename: 	GuessTheNumber.java
 * Created: 	9-28-2012 by MH
 *
 * Purpose: 	Conversion of Guess the Number Game from C++ to Java
 *
 */

import javax.swing.*;     // GUI
import java.util.Random;  // Randomizer

public class GuessTheNumber
{

   //main method
   public static void main ( String[] args )
   {

      //declare and initialize variables
      int compnum, yournum, tries;
      String selectyn, openingMessage, instructionMessage, attemptMessage, yournumString, windowMessage;

      //display opening messages
      openingMessage  = "Find and defuse the bomb!";
      JOptionPane.showMessageDialog( null, openingMessage );
      selectyn = "y";

      // game routine
      do
      {
          instructionMessage  = "Guess a number from 1 to 10.  You have three tries.";
          JOptionPane.showMessageDialog( null, instructionMessage );


          Random rand = new Random();        // random object
          compnum = rand.nextInt(10)+1;  // random number from 1 to 10

          tries = 0;
	  while (tries < 4)
	  {
              tries++;

              // get required input using dialog boxes
              attemptMessage = "Attempt number " + tries + ":";
              yournumString = JOptionPane.showInputDialog ( attemptMessage );
              yournum = Integer.parseInt( yournumString );//convert string to integer

	      // determine if numbers match
	      if (compnum == yournum)
              {
                  //congratulations, play again?
		  windowMessage = "Conrgatulations!!! \n";
                  JOptionPane.showMessageDialog( null, windowMessage );
		  PlayAgain();
              }
	      else
		 {
		 if ((compnum > yournum) && (tries < 3))
		    {
                       windowMessage = "Uh oh.  The secret number is higher. \n";
                       JOptionPane.showMessageDialog( null, windowMessage );

                    }
                    else
                       {
                          if ((compnum < yournum) && (tries < 3))
                             {
                                 windowMessage = "Uh oh.  The secret number is lower. \n";
                                 JOptionPane.showMessageDialog( null, windowMessage );
                             }
                       }
                 }

              if ((tries ==3) && (compnum != yournum))
                 {
                       windowMessage = "KABOOOM!!!  The secret number was " + compnum + ". \n\n";
                       JOptionPane.showMessageDialog( null, windowMessage );
		       PlayAgain();
                 }
           }

   }  // end do
     while (selectyn.equals("y"));
     System.exit(0);
} // end main


public static void PlayAgain()
   {
        int tries;
        String ynNoSelected = "n";
        String selectyn, selectynMessage;
        selectynMessage = "Would you like to play again (y/n)?";
        selectyn = JOptionPane.showInputDialog( selectynMessage );
        if (selectyn.equals(ynNoSelected))
           {
         System.exit(0);         
           }
              else
                 {
                    tries = 0;
                 }
   }
            
} // end class

I've printed out the code and am trying to reason if I used the proper commands and position in the program. Thanks.

[pakupakuman]

I believe I solved it!

I eliminated lines 90, 99-102, and changed line 39 from "tries < 4" to "tries < 3":

/*
 * Filename: 	GuessTheNumber.java
 * Created: 	9-28-2012 by MH
 *
 * Purpose: 	Conversion of Guess the Number Game from C++ to Java
 *
 */

import javax.swing.*;     // GUI
import java.util.Random;  // Randomizer

public class GuessTheNumber
{

   //main method
   public static void main ( String[] args )
   {

      //declare and initialize variables
      int compnum, yournum, tries;
      String selectyn, openingMessage, instructionMessage, attemptMessage, yournumString, windowMessage;

      //display opening messages
      openingMessage  = "Find and defuse the bomb!";
      JOptionPane.showMessageDialog( null, openingMessage );
      selectyn = "y";

      // game routine
      do
      {
          instructionMessage  = "Guess a number from 1 to 10.  You have three tries.";
          JOptionPane.showMessageDialog( null, instructionMessage );


          Random rand = new Random();        // random object
          compnum = rand.nextInt(10)+1;  // random number from 1 to 10

          tries = 0;
	  while (tries < 3)
	  {
              tries++;

              // get required input using dialog boxes
              attemptMessage = "Attempt number " + tries + ":";
              yournumString = JOptionPane.showInputDialog ( attemptMessage );
              yournum = Integer.parseInt( yournumString );//convert string to integer

	      // determine if numbers match
	      if (compnum == yournum)
              {
                  //congratulations, play again?
		  windowMessage = "Conrgatulations!!! \n";
                  tries = 0;
                  JOptionPane.showMessageDialog( null, windowMessage );
		  PlayAgain();
              }
	      else
		 {
		 if ((compnum > yournum) && (tries < 3))
		    {
                       windowMessage = "Uh oh.  The secret number is higher. \n";
                       JOptionPane.showMessageDialog( null, windowMessage );

                    }
                    else
                       {
                          if ((compnum < yournum) && (tries < 3))
                             {
                                 windowMessage = "Uh oh.  The secret number is lower. \n";
                                 JOptionPane.showMessageDialog( null, windowMessage );
                             }
                       }
                 }

              if ((tries ==3) && (compnum != yournum))
                 {
                       windowMessage = "KABOOOM!!!  The secret number was " + compnum + ". \n\n";
                       JOptionPane.showMessageDialog( null, windowMessage );
		       PlayAgain();
                 }
           }

   }  // end do
     while (selectyn.equals("y"));
     System.exit(0);
} // end main


public static void PlayAgain()
   {
        String ynNoSelected = "n";
        String selectyn, selectynMessage;
        selectynMessage = "Would you like to play again (y/n)?";
        selectyn = JOptionPane.showInputDialog( selectynMessage );
        if (selectyn.equals(ynNoSelected))
           {
         System.exit(0);         
           }
   }
            
} // end class

Anybody would like to confirm? Thanks.