java

import javax.swing.JFrame;

public class TicTacToe {

    static String[][] tab = new String[4][4];

    public static void main(String[] args) {

        String[][] tab = new String[4][4];

        tab[0][0] = "  ";
        tab[0][1] = " 1 ";
        tab[0][2] = " 2 ";
        tab[0][3] = " 3 ";

        tab[1][0] = " 1 ";
        tab[1][1] = "   ";
        tab[1][2] = "   ";
        tab[1][3] = "   ";
        tab[2][0] = " 2 ";
        tab[2][1] = "   ";
        tab[2][2] = "   ";
        tab[2][3] = "   ";
        tab[3][0] = " 3 ";
        tab[3][1] = "   ";
        tab[3][2] = "   ";
        tab[3][3] = "   ";

        for(int i = 0; i < 4; ++i) {
            for(int j = 0; j < 4; ++j) {
                System.out.print(tab[i][j]);
            }
            System.out.println("");
        }

        Window window = new Window();
        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        window.setVisible(true);


        }

        public static boolean addCharacterUser(int y, int x) {
            if(tab[y][x].equals(" X ") || tab[y][x].equals(" O ")) {
                System.out.println("");
                System.out.println("This position is occupied!");
                System.out.println("");

                return false;
            } else {
                tab[y][x] = " X ";
                return true;
            }
        }

}