Adding a usedChar array in my program

[Klaas Vredevort]

OK, I'm writing a Hangman program and it has three classes, Hangman, HangmanFileReader (it gets the words out of a file) and HangmanManager (which acts as a driver)

The program runs 100% the way I want it, except for one thing: If the user guesses a letter they have guessed correctly or incorrectly before, it still subtracts from their chances left.

What I want to do is add an array of chars, which contains the letters the user has already guessed. Then, if he guesses a letter he has guessed before, the computer says to that the letter has been used, and does not subtract it from the chances he has left.

I have declared the array as

      char [] letterHasBeenUsed;  

in the Hangman class, which I will paste here. I certainly do not expect of you to go through the entire thing, but I think it should help you. Here is is:

 //package za.co.testing.hangman;
 
import java.io.*;
 
/**
 * <p>Title: Hangman</p>
 *
 * @author Jaco Gillman
 * @version 1.0
 */
public class Hangman
{
 
    private StringBuffer wordToPlayWith;
    private StringBuffer wordToGuess;
    private char [] wordToPlayWithCharArray;
    private char [] guessedCharArray;
    private int numberOfTries;
    private boolean hasGuessed = false;
    int tries = 0;
    char [] letterHasBeenUsed;
 
    /**
     * @param wordToPlayWith String
     */
    public Hangman (String wordToPlayWith)
    {
        this.wordToPlayWith = new StringBuffer (wordToPlayWith);
        this.numberOfTries = wordToPlayWith.length () + 5;
        this.wordToGuess = new StringBuffer (128);
        this.wordToPlayWithCharArray = (this.wordToPlayWith.toString ()).toCharArray ();
    }
 

    /**
     * @throws IOException
     */
    public void play () throws IOException
    {
 

 
        int wordToPlayWithLength = wordToPlayWith.length ();
        System.out.println ("The word to guess has " + wordToPlayWithLength + " characters.");
 
        for (int i = 0 ; i < wordToPlayWithLength ; i++)
        {
            wordToGuess.append ("-");
        }
 
        BufferedReader input = new BufferedReader (new InputStreamReader (System.in));
 
        while (tries < numberOfTries && !hasGuessed)
        {
 
            System.out.println ("The word to guess is: " + wordToGuess.toString ());
            System.out.println ("Please enter a single character: ");
            String charChosen = input.readLine ();
 
            while (charChosen.length () > 1 || charChosen.length () == 0)
            {
                System.out.println ("The word to guess is: " + wordToGuess.toString ());
                System.out.println ("Please enter a single character: ");
                charChosen = input.readLine ();
            }
            guessedCharArray = charChosen.toCharArray ();
            char guessedChar = guessedCharArray [0];
 
            for (int j = 0 ; j < wordToPlayWithCharArray.length ; j++)
            {
 
                if (wordToPlayWithCharArray [j] == guessedChar)
                {
                    wordToGuess = wordToGuess.insert (j, guessedChar);
                    wordToGuess = wordToGuess.delete (j + 1, j + 2);
                }
            }
 
            if (this.wordToPlayWith.toString ().equals (this.wordToGuess.toString ()))
            {
                System.out.println ("Well done!! You've guessed the word.");
                hasGuessed = true;
            }
 
            if (!hasGuessed)
            {
                tries++;
                System.out.println ("You've got " + (numberOfTries - tries) + " tries left!");
            }
        }
 
        if (!hasGuessed)
        {
            System.out.println ("Sorry! Beter luck next time.");
        }
    }
}
   

What do you think? should it actually test for the letter before it does anything else?

Your help is greatly appreciated!

Klaas

[Stephen Foy]

 
char[]letters = new char[25];
int counter = 0;
 
if(guessedLetter != realLetter) {
   letters[counter] = guessedLetter;
   counter++;
}
 
for(int i = 0;i <= letters.length;i++) {
   if(letters[i] == guessedLetter) {
      System.out.println("You have tried this letter");
   }
}
 

[Garrett Rowe]

Originally posted by Stephen Foy:

 
char[]letters = new char[25];
int counter = 0;
 
if(guessedLetter != realLetter) {
   letters[counter] = guessedLetter;//*1
   counter++;
}
 
for(int i = 0;i <= letters.length;i++) {//*2
   if(letters[i] == guessedLetter) {
      System.out.println("You have tried this letter");
   }
}
 

In this bit of code, you are adding the guessedLetter to the letters array in the line I've marked *1, and then you iterate through the letters array to see if the letter is there in the line I marked *2. Therefore the letter will always be found and the message will always print. The genral premise will work but the logic is a little off.

[Garrett Rowe]

I think an ArrayList<Character> would also work well in this situation.

List<Character> usedLetters = new ArrayList<Character>();
 
//Test to see if guessedLetter has already been used
if (usedLetters.indexOf(guessedLetter) >= 0)
{
   System.out.println("You've tried that letter already");
}
 
else
{
   //If it hasn't been used, add it to list
   usedLetters.add(guessedLetter);
 
   //...add logic to test whether the guessedLetter appears in the puzzle
 
}

If you're not familiar with the ArrayList class, you can check out the documentation here.

Garrett

[Rusty Shackleford]

I think a good solution is to just have one array(or ArrayList is you prefer), with every character in the alphabet, when the player picks a char, it is removed from the array. If it isn't found, then you know it was used already.

Your way works just fine, this is just a slightly more efficient and smaller solution.

You definately want to check to see if it has been used already, since the proper behavior of the program depends on that being doen first.
[ March 05, 2006: Message edited by: Rusty Shackleford ]

[Stephen Foy]

 
// get input...
 
for(int i = 0;i <= letters.length;i++) {
   if(letters[i] == guessedLetter) {      
      System.out.println("You have tried this letter");   
   } else if(guessedLetter != realLetter) {
      letters[counter] = guessedLetter;
   }
}

Ugh, my logic sucks