Java Console Game Hacks • 10 min read

import java.util.Random;
import java.util.Scanner;

public class TicTacToeGame {
    private static final int SIZE = 3;
    private char[][] board = new char[SIZE][SIZE];
    private char playerMark, computerMark;
    private Random random = new Random();

    public TicTacToeGame() {
        for (int i = 0; i < SIZE; i++) {
            for (int j = 0; j < SIZE; j++) {
                board[i][j] = '-';
            }
        }
    }

    public boolean isBoardFull() {
        for (int i = 0; i < SIZE; i++) {
            for (int j = 0; j < SIZE; j++) {
                if (board[i][j] == '-') {
                    return false;
                }
            }
        }
        return true;
    }

    public void printBoard() {
        for (int i = 0; i < SIZE; i++) {
            for (int j = 0; j < SIZE; j++) {
                System.out.print(board[i][j] + " ");
            }
            System.out.println();
        }
    }

    public boolean checkWin() {
        return checkRowsForWin() || checkColumnsForWin() || checkDiagonalsForWin();
    }

    private boolean checkRowsForWin() {
        for (int i = 0; i < SIZE; i++) {
            if (board[i][0] == board[i][1] && board[i][1] == board[i][2] && board[i][0] != '-') {
                return true;
            }
        }
        return false;
    }

    private boolean checkColumnsForWin() {
        for (int i = 0; i < SIZE; i++) {
            if (board[0][i] == board[1][i] && board[1][i] == board[2][i] && board[0][i] != '-') {
                return true;
            }
        }
        return false;
    }

    private boolean checkDiagonalsForWin() {
        return (board[0][0] == board[1][1] && board[1][1] == board[2][2] && board[0][0] != '-') ||
               (board[0][2] == board[1][1] && board[1][1] == board[2][0] && board[0][2] != '-');
    }

    public void changePlayer() {
        playerMark = (playerMark == 'X') ? 'O' : 'X';
        computerMark = (computerMark == 'X') ? 'O' : 'X';
    }

    public void computerTurn() {
        int computerMove;
        while (true) {
            computerMove = random.nextInt(9) + 1;
            if (isValidMove(String.valueOf(computerMove))) {
                break;
            }
        }
        System.out.println("Computer chose " + computerMove);
        placeMark(String.valueOf(computerMove), computerMark);
    }

    public boolean isValidMove(String position) {
        switch (position) {
            case "1":
                return (board[0][0] == '-');
            case "2":
                return (board[0][1] == '-');
            case "3":
                return (board[0][2] == '-');
            case "4":
                return (board[1][0] == '-');
            case "5":
                return (board[1][1] == '-');
            case "6":
                return (board[1][2] == '-');
            case "7":
                return (board[2][0] == '-');
            case "8":
                return (board[2][1] == '-');
            case "9":
                return (board[2][2] == '-');
            default:
                return false;
        }
    }

    public void placeMark(String position, char mark) {
        switch (position) {
            case "1":
                board[0][0] = mark;
                break;
            case "2":
                board[0][1] = mark;
                break;
            case "3":
                board[0][2] = mark;
                break;
            case "4":
                board[1][0] = mark;
                break;
            case "5":
                board[1][1] = mark;
                break;
            case "6":
                board[1][2] = mark;
                break;
            case "7":
                board[2][0] = mark;
                break;
            case "8":
                board[2][1] = mark;
                break;
            case "9":
                board[2][2] = mark;
                break;
            default:
                System.out.println("Invalid position");
        }
    }

    public void playGame() {
        Scanner scan = new Scanner(System.in);
        System.out.println("Welcome to Akshat's Tic Tac Toe!");
        System.out.println("To play, enter any number from 1-9 to indicate your move!");
        printBoard();
        System.out.println("Choose your mark: X or O");
        playerMark = scan.nextLine().charAt(0);
        if (playerMark == 'X') {
            computerMark = 'O';
        } else {
            computerMark = 'X';
        }

        while (true) {
            System.out.println("Enter your placement (1-9):");
            String userInput = scan.nextLine();
            if (isValidMove(userInput)) {
                placeMark(userInput, playerMark);
                printBoard();
                if (checkWin()) {
                    System.out.println("Player wins!");
                    break;
                }
                if (isBoardFull()) {
                    System.out.println("It's a tie!");
                    break;
                }
                computerTurn();
                printBoard();
                if (checkWin()) {
                    System.out.println("Computer wins!");
                    break;
                }
                if (isBoardFull()) {
                    System.out.println("It's a tie!");
                    break;
                }
            } else {
                System.out.println("Invalid position. Try again.");
            }
        }
    }
}

TicTacToeGame game = new TicTacToeGame();
game.playGame(); 

Welcome to Akshat's Tic Tac Toe!
To play, enter any number from 1-9 to indicate your move!
- - - 
- - - 
- - - 
Choose your mark: X or O
Enter your placement (1-9):
- X - 
- - - 
- - - 
Computer chose 4
- X - 
O - - 
- - - 
Enter your placement (1-9):
X X - 
O - - 
- - - 
Computer chose 6
X X - 
O - O 
- - - 
Enter your placement (1-9):
X X X 
O - O 
- - - 
Player wins!