Thread: TicTacToe

Hello! I have this code here

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 = In.readInt() -1;
		Out.print("Enter a coloumn:");
		col = In.readInt() -1;
		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;
}

And it works fine.Now I want to implement a "safety" mechanicsm in the code.What I mean is I want to make sure that no wrong inputs (regarding rows and coloumns) can be made. So the range is from 1 - 3 and I want when the users puts in lets say 4, a message pops on on the screen saying that that is not a valid input. I want to execute this WITHOUT exceptions.I was thinking of creating a method (boolean) that will take an input compare it to a lower and upperbound and return true or false accordingly.My only issue is how will I implement that in the play method. Any help?

Thanks!

Hey, so do you mean to implement this as an "standalone" method or a part of a method?

Okay i'll try and implement this in this play method, I'll let you know what happens.Thanks!

--- Update ---

Okay so I've tried a few things and this is what I have come up with;

while(playing){
		Out.println();
		Out.println("Player:" +" "+ turn);
		Out.print("Enter a row:");
		row = In.readInt() -1;
		if(row > 3 || row < 1) {
			Out.println("Invalid input");
		}
		Out.print("Enter a coloumn:");
		col = In.readInt() -1;
		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';
		}
	}
}

And i get an ArrayOutOfBoundIndex error, which excatly what I'm trying to avoid.What am I doing wrong on this loop?

Okay so Im not sure how to implement it in a single method, so I did it in two.

public static int readNumber() {
	boolean isValid = false;
	int number;
	do {	
 
	number = In.readInt() - 1;
 
	if (!In.done()) {
        Out.println("Invalid input");
        In.readLine(); 
      } else if (number < 1 || number > 3) {
        Out.println("Number must be between 1 and 3");
      } else {
        isValid = true;
      }
    } while (!isValid);
 
    return number;
  }
}

Now I'm kinda having issues with this if loop.What I mean is when I input 1 it prints out the message,although it shouldnt What am I missing?

1 2 3

Actually no, I have teste the code and it works just like intended.If I input 1 and 1 for row and coloumn the very top left field will be marked. Without reading in the Input that way you would have to use 0 1 2, to initialize the fields, meaning the very first field would be 0 0.Which kinda isnt so wanted and user friendly.PS I have fixed the issue

public static int readNumber() {
	boolean isValid = false;
	int number;
	do {	
 
	number = In.readInt() - 1;
 
	if (!In.done()) {
        Out.println("Invalid input");
        In.readLine(); 
      } else if (number < 0 || number > 3) {
        Out.println("Number must be between 1 and 3");
      } else {
        isValid = true;
      }
    } while (!isValid);
 
    return number;
  }
}