TicTacToe - Objects

Question

Hey guys, I've been working on an objected-oriented tic-tac-toe game to get acquainted with the language, etc...
I'm having problems with the checkMove(int) method, in the board object. No matter what, the value returned is always true, even if the move is legal (in which case the value returned should be false). Here is the code:
Board object:
public class Board {
  private String[][] _board = new String[3][3];
  public Board() {
   int x = 0;
   for (int row = 0;  row < 3;  row++) {
     for (int column = 0;  column < 3;  column++) {
       x += 1;
       _board[row][column] = " " +x +" ";
  }   // End of constructor.
    public boolean checkMove(int position) {
    boolean test = false;
    switch (position) {
      case 1: {if (_board[0][0] != " " +1 +" ") {test = true;} break;}
      case 2: {if (_board[0][1] != " " +2 +" ") {test = true;} break;}
      case 3: {if (_board[0][2] != " " +3 +" ") {test = true;} break;}
      case 4: {if (_board[1][0] != " " +4 +" ") {test = true;} break;}
      case 5: {if (_board[1][1] != " " +5 +" ") {test = true;} break;}
      case 6: {if (_board[1][2] != " " +6 +" ") {test = true;} break;}
      case 7: {if (_board[2][0] != " " +7 +" ") {test = true;} break;}
      case 8: {if (_board[2][1] != " " +8 +" ") {test = true;} break;}
      case 9: {if (_board[2][2] != " " +9 +" ") {test = true;} break;}
      default: {test = true; break;}
    }   // End of switch.
    return test;
  } // End of method checkMove().
}   // End of class Board.The relevant part of the main code is:
do {
          System.out.println(player1.getName() +", it is your turn. Where would you like to play?"); 
          position = TextIO.getlnInt();
          illegalMove = board.checkMove(position);
        } while(illegalMove == true);Any corrections and general criticism is greatly appreciated :)

Answer 1

cotton.m wrote:
A few comments. This
the value returned is always true, even if the move is legal (in which case the value returned should be false).Seems logically backwards to me. A method called checkMove I would expect to return true for legal and false for illegal. But maybe that's just me.You are completely right. However, it just so happened that in the main method, I had the variable illegalMove. Therefore it makes sense that illegalMove is true when there is an illegalMove, and illegalMove is false when there isnt.
cotton.m wrote:
Another comment would be that I wouldn't use an array of Strings for the board. Why not ints? (or enums or bytes) Well ints anyway. I mean you only have three options right? X, O or empty. Storing 9 different strings is a pain now and going to be worse later when you check the results (to look for a winner or the "right" place to move next)Sorry for the possible naivet of this question, but how would you create an array of enums or bytes, and how would you apply it to this situation? seems like an interesting option.
Actually, i already had a method called checkWin() which was working. In fact, it was just this checkMove() method which wasnt working.
corlettk wrote:
Looks like an epic brainfart to me... if 1..9 then true, else true. Huh? In my (very limited) understanding, the default case just takes into account any possible input from the user which surpasses the values of 1-9, thus not being located on the board, which would classify it as an illegal move.
Thanks for all of the help guys, I really appreciate it :)