Thread: Checking for taken places in TicTacToe

boolean method that ... say taken

That sounds reasonable.

Now you need the same kind of loop that was used in the readNumber method. Don't exit the loop until the user has chosen a valid square.

So I need a do while loop? I'll try it.


EDIT: So I've tried it but now,after my first Input the program just stops.

 
public class TicTacToe {
	public static int row,col;
	public static char[][] board = new char[3][3];
	public static char turn = 'X';
 
	public static void main(String[] args) {
		for(int i = 0; i < 3; i++) {
			for(int j = 0; j < 3; j++) {
				board[i][j] = '_';
			}
		}
		Play();
	}
 
	public static void printBoard() {
	for(int i = 0; i < 3; i++) {
		Out.println();
		for(int j = 0; j < 3; j++) {
			if(j == 0){
				Out.print("| ");
			}
			Out.print(board[i][j] + " | ");
		}
	}
	Out.println();
 
}
 
 
public static void Play() {
	boolean playing = true;
	printBoard();
	Out.println();
	int nOfTurns = 1;
	Out.println("Turn: " + nOfTurns);
 
	while(playing){
		Out.println();
		Out.println("Player:" +" "+ turn);
		Out.print("Enter a row:");
		row = readNumber();
		Out.print("Enter a coloumn:");
		col = readNumber();
		do {
			if(isTaken(row,col)) {
				Out.println("That cell is taken");
			}
		}while(!isTaken(row,col));
		board[row][col] = turn;
		nOfTurns++;
		Out.println();
		Out.println("Turn: "+ nOfTurns);
		if(GameOver(row,col)) {
			playing = false;
			Out.println("Player" +" "+turn +" "+"has won!");
		}
		printBoard();
 
		if(turn == 'X') {
			turn = 'O';
		}else{
			turn = 'X';
		}
	}
}
 
public static boolean GameOver(int rowMove,int colMove) {
	if(board[0][colMove] == board[1][colMove] && board[0][colMove] == board[2][colMove]){
		return true;
	}else if(board[rowMove][0] == board[rowMove][1] && board[rowMove][0] == board[rowMove][2]) {
		return true;
	}else if(board[0][0] == board[1][1] && board[0][0] == board[2][2] && board[1][1] != '_') {
		return true;
	}else if(board[0][2] == board[1][1] && board[0][2] == board[2][0] && board[1][1] != '_') {
		return true;
	}else
		return false;
}
 
 
public static int readNumber() {
	boolean isValid = false;
	int number;
	do {	
 
	number = In.readInt() - 1;
 
	if (!In.done()) {
        Out.println("Input must be a valid number");
        In.readLine(); 
      } else if (number < 0 || number > 2) {
        Out.println("The number is not in the specified range: 1-3");
      } else {
        isValid = true;
      }
    } while (!isValid);
 
    return number;
  }
 
public static boolean isTaken(int row, int col) {
	return board[row][col] != '_';
}
 
}

When will the method change what value it returns? If its args are always the same, it should return the same value, forever.
The loop needs to include code that changes the values of the args passed to the method so the method has a chance to return a different value.

Okay, I'll see what I can do

EDIT: Didnt help, maybe I got it wrong?

 
public class TicTacToe {
	public static int row,col;
	public static char[][] board = new char[3][3];
	public static char turn = 'X';
 
	public static void main(String[] args) {
		for(int i = 0; i < 3; i++) {
			for(int j = 0; j < 3; j++) {
				board[i][j] = '_';
			}
		}
		Play();
	}
 
	public static void printBoard() {
	for(int i = 0; i < 3; i++) {
		Out.println();
		for(int j = 0; j < 3; j++) {
			if(j == 0){
				Out.print("| ");
			}
			Out.print(board[i][j] + " | ");
		}
	}
	Out.println();
 
}
 
 
public static void Play() {
	boolean playing = true;
	printBoard();
	Out.println();
	int nOfTurns = 1;
	Out.println("Turn: " + nOfTurns);
 
	while(playing){
		Out.println();
		Out.println("Player:" +" "+ turn);
		Out.print("Enter a row:");
		row = readNumber();
		Out.print("Enter a coloumn:");
		col = readNumber();
		do {
			if(isTaken(row,col)) {
				Out.println("That cell is taken,please enter another cell");
				row = readNumber();
				col = readNumber();
			}
		}while(!isTaken(row,col));
		board[row][col] = turn;
		nOfTurns++;
		Out.println();
		Out.println("Turn: "+ nOfTurns);
		if(GameOver(row,col)) {
			playing = false;
			Out.println("Player" +" "+turn +" "+"has won!");
		}
		printBoard();
 
		if(turn == 'X') {
			turn = 'O';
		}else{
			turn = 'X';
		}
	}
}
 
public static boolean GameOver(int rowMove,int colMove) {
	if(board[0][colMove] == board[1][colMove] && board[0][colMove] == board[2][colMove]){
		return true;
	}else if(board[rowMove][0] == board[rowMove][1] && board[rowMove][0] == board[rowMove][2]) {
		return true;
	}else if(board[0][0] == board[1][1] && board[0][0] == board[2][2] && board[1][1] != '_') {
		return true;
	}else if(board[0][2] == board[1][1] && board[0][2] == board[2][0] && board[1][1] != '_') {
		return true;
	}else
		return false;
}
 
 
public static int readNumber() {
	boolean isValid = false;
	int number;
	do {	
 
	number = In.readInt() - 1;
 
	if (!In.done()) {
        Out.println("Input must be a valid number");
        In.readLine(); 
      } else if (number < 0 || number > 2) {
        Out.println("The number is not in the specified range: 1-3");
      } else {
        isValid = true;
      }
    } while (!isValid);
 
    return number;
  }
 
public static boolean isTaken(int row, int col) {
	return board[row][col] != '_';
}
 
}

EDIT: Need to change the do while loop,the part where the while loop should end while(isTaken(row,cel)) without the negation.Works now.

Thanks Norm, your the man!