====== Tic-Tac-Toe: 2D array ======
This will be a text based implementation but would be easy to port into a graphic based version.

{{ :tictactoe2.java |TicTacToe2.java}}

  - Complete the constructor so the board can be any size, not just 3 by 3. Read the comments for details
  - complete the ''changePlayer'' method.
  - complete the ''mark'' method, that only replaces the grid location with the letter stored in ''player'' if it currently has a space.   call the ''changePlayer'' method (Don't reduplicate code inside the ''mark'' method).
  - complete the ''getPlayer'' method
  - make a method called ''movesRemaining'' that returns the number of spaces in ''grid''. Try using an enhanced ("for-each") for loop.
  - write a main method that makes an instance of the TicTacToe2 class and the calls the ''print'' method:
''public static void main(String[] args)''

At this point you can test your code with {{ :tictactoetextgame.java |TicTacToeTexGame.java}} to see if you can put "X" and "O" in all 9 squares.  Without completing the winner method, it will end with a cat's game every time.  Try making sure it does not allow overwriteing a square that already has an "X" or a "O".

Next we can work on the game, and the testing the ''winner()'' method of the ''TicTacToe2'' class. 

{{ :tictactoetextgame.java |TicTacToeTexGame.java}}

{{ ::winnertester.java |WinnerTester.java}}