TicTacToe.java

import  java.util.Scanner;
public class TicTacToe {
    public static void main(String[] args) {
        char board[][] = new char[3][3];
        for(int row = 0; row< board.length; row++) {
            for(int col = 0; col<board[row].length; col++) {
                board[row][col] = ' ';
            }
        }

        char player = 'X';
        boolean gameOver = false;
        Scanner scanner = new Scanner(System.in);

        while(!gameOver) {
            printBoard(board);
            System.out.println("player" +  player + "enter:");
            int row = scanner.nextInt();
            int col = scanner.nextInt();

            if(board[row][col] == ' ') {
                board[row][col] = player;
                gameOver = haveWon(board,player);
                if(gameOver) {
                    System.out.println("player" +  player + "has won!");
                } else  {
                    if(player=='X') {
                        player = 'O';
                    } else  {
                        player = 'X';
                    }
                }

            }else {
                System.out.println("Oops! Invalid move ");
            }
        }
        printBoard(board);
    }

    private static boolean haveWon(char[][] board, char player) {
        for(int row = 0; row < board.length; row++) {
            if(board[row][0] == player && board[row][1] == player && board[row][2] == player) {
                return true;
            }
        }
        for(int col = 0; col < board[0].length; col++) {
            if(board[0][col] == player && board[1][col] == player && board[2][col] == player) {
                return true;
            }
        }
        if(board[0][0] == player && board[1][1] == player && board[2][2]==player){
            return true;
        }
        if(board[0][2] == player && board[1][1] == player && board[2][0]==player){
            return true;
        }
        return  false;

    }

    private static void printBoard(char[][] board) {
        for(int row = 0; row< board.length; row++) {
            for(int col = 0; col<board[row].length; col++) {
                System.out.print(board[row][col] + " | ");
            }
            System.out.println();
        }

    }
}