GameOver does not appear

Question

I have programmed a TicTacToe game. I created a list for checking if the game is over or still going on (checkGameOver). And the other one looks similiar but it is for checking who has won and it should print out, that player 1 or player 2 had won. When I run the game and when I play the top row fields 1 2 3. The computer print the message that the process is finished. But when I play the fiels 4 5 6 or anyother else the game do not finish.

Please let me know if you know the problem than I could send you the whole code.

   *public static boolean checkGameOver(char [][] gameBoard){
    List topRow = Arrays.asList(1, 2, 3);
    List midRow = Arrays.asList(4, 5, 6);
    List botRow = Arrays.asList(7, 8, 9);

    List leftCol = Arrays.asList(1, 4, 7);
    List midCol = Arrays.asList(2, 5, 8);
    List rightCol = Arrays.asList(3, 6, 9);

    List cross1 = Arrays.asList(1, 5, 9);
    List cross2 = Arrays.asList(7, 5, 3);

    List<List> gameOver = new ArrayList<List>();
    gameOver.add(topRow);
    gameOver.add(midRow);
    gameOver.add(botRow);
    gameOver.add(leftCol);
    gameOver.add(midCol);
    gameOver.add(rightCol);
    gameOver.add(cross1);
    gameOver.add(cross2);

    for(List l : gameOver) {
        if(playerPositions.containsAll(l) || computerPositions.contains(l)) {
            return true;
        } else {
            return false;
        }
    }

    return false;
}

public static String checkWinner(char [][] gameBoard) {

    List topRow = Arrays.asList(1, 2, 3);
    List midRow = Arrays.asList(4, 5, 6);
    List botRow = Arrays.asList(7, 8, 9);

    List leftCol = Arrays.asList(1, 4, 7);
    List midCol = Arrays.asList(2, 5, 8);
    List rightCol = Arrays.asList(3, 6, 9);

    List cross1 = Arrays.asList(1, 5, 9);
    List cross2 = Arrays.asList(7, 5, 3);

    List<List> gameOver = new ArrayList<List>();
    gameOver.add(topRow);
    gameOver.add(midRow);
    gameOver.add(botRow);
    gameOver.add(leftCol);
    gameOver.add(midCol);
    gameOver.add(rightCol);
    gameOver.add(cross1);
    gameOver.add(cross2);

    for(List l : gameOver) {
        if(playerPositions.containsAll(l)) {
            return "Glückwunsch du hast gewonnen!";
        } else if(computerPositions.contains(l)) {
            return "Computer hat gewonnen!";
        } else if(playerPositions.size() + computerPositions.size() == 9) {
            return "Unentschieden!";
        }
    }

    return "";
}*

Answer 1

Remove the "return false;" in the else.

    for(List l : gameOver) {
        if(playerPositions.containsAll(l) || computerPositions.contains(l)) {
            return true;
        } else {
            return false;  // Remove this.
        }
    }

Assuming gameOver isn't empty, this loop only executes for the first element, because it always returns from within the loop body.

---

It's far from ideal that you duplicate the game over logic in the method for checking whether there is a winner, and the method for checking who is the winner.

You should define an enum as the return value of the checkGameOver method:

enum Winner {
  PLAYER, COMPUTER, NONE
}

Then you can do something like:

for(List l : gameOver) {
   if (playerPositions.containsAll(l)) return Winner.PLAYER;
   if (computerPositions.containsAll(l)) return Winner.COMPUTER;
}
return Winner.NONE;

Then you can check the return value of the method (e.g. with a switch) to print out the corresponding message.