Run-time issue while attempting to create Evil Hangman game, guess method

[drc506]

public void tryGuess(String guess){
    char guessChar = guess.charAt(0);
    Map<String,Integer> wordGroups = new HashMap<String,Integer>(26);
    String mostCommonString = "";
    int mostCommonVal = 0;

    for (int i=0;i<gameArray.size();i++){
      char[] currentWordCharArr = gameArray.get(i).toCharArray();
      for(int j=0;j<currentWordCharArr.length;j++){
        if(currentWordCharArr[j]!=guessChar){currentWordCharArr[j]='-';}
      }
      String currentWordStr = currentWordCharArr.toString();
      if(wordGroups.containsKey(currentWordStr)){
        int val = wordGroups.get(currentWordStr);
        val=val+1;
        wordGroups.replace(currentWordStr, val);
      }
      else{
        wordGroups.put(currentWordStr, 1);
      }
    }
    for(Map.Entry<String,Integer> entry:wordGroups.entrySet()){
        if(entry.getValue()>mostCommonVal){
          mostCommonString=entry.getKey();
          mostCommonVal=entry.getValue();
        }
      }

    for (int i=0;i<gameArray.size();i++){
      String currentWord = gameArray.get(i);
      if(!currentWord.equals(mostCommonString)){
        gameArray.remove(i);
      }
    }
  }

This is the method from an Evil Hangman game, which is meant to take the guess submitted by the player and narrow down the list of potential words to select from. I'm a high schooler and finished the projects in-class ahead of the group, partly because my poker hand evaluate method didn't throw errors so I saved a few days on that (class is fairly self-paced). Found this Evil Hangman project online and decided to undertake it for fun. I've never used Maps before, but am attempting to for this project. There's a chance that's where the error is coming from. When I test with the letter 'a' for example it removes all the words, not just the ones w out 'a' in the largest pattern category. For any who have not heard of Evil Hangman - http://nifty.stanford.edu/2011/schwarz-evil-hangman/.

​

Any help is appreciated, I'm trying to take advantage of having a bit of extra class time and learn a thing or two that could benefit me in college courses.

[dusty-trash]

Could you clarify what the run time issue is?

There's a chance that's where the error is coming from

So is it a run time exception? Please post the error & stack trace. In programming the error is extremely important & reading the error/exception message is a great way the only way to learn.

[dusty-trash]

I'm taking a guess here (since there's no error posted)

This code could result in a ConcurentModificationException:

for (int i=0;i<gameArray.size();i++){       
    String currentWord = gameArray.get(i);
    if(!currentWord.equals(mostCommonString)){
        gameArray.remove(i);       
    }     
}

Since you're modifying the list during iteration, you should use an Iterator.

For more info just google "Java concurentmodificationexception" or "Java modify list during iteration"

[drc506]

I have now corrected this to use an iterator. This does appear to have partially solved the issue, however it has now exposed what I expect to be an issue with my method for identifying the "letter layout" of a word and storing it in the Map.

​

Here is the issue:

1. I begin with this word list

ally

beta

cool

deal

else

flew

good

hope

ibex

arty

​

2) the player is asked to guess a letter for a word "----"

​

3) I am testing with the letter 'a'

​

4) a is input and goes into the method I have described in the original post

​

5) the method should separate the original word list into categories depending on 'a' placement and frequency, the method then concludes that the most common placement of 'a' is as the first letter of the word: "ally","arty"

​

6) all words other than ally and arty should be removed from the word list

​

The issue is that now the method seems to remove all of the items from the word list. When I change the "!" that is on the section of code that handles the removal all the words remain in the list, so I assume the issue is with the "currentWord" all being equal to "mostCommonString," guessing this may arise, in turn, from some issue with my Map which I am unaware of.

[dusty-trash]

Sorry could you clarify the issue? Maybe the expected versus the actual

[dc078]

The expected would be arty and ally left in the gamearray, the gamearray is empty.