How to make java TicTacToe table?

Question

How do I create a 3x3 without changing the given method?

I will need to create 4 methods beside the main method, but I am stuck on the display board.

Do I need to create a variable or something that represent each number so that I can use it to update the board each time after the user enter a move?

it's supposed to look like this:

1 2 3

4 5 6

7 8 9

the following is the main method can't be changed.

public class TicTacToe {
    public static void main (String args[]) {  
    char[] board = {'1', '2', '3', '4', '5', '6', '7', '8', '9'};
    char move = 'O';
    displayBoard(board);

    while (!checkWinner(board, move)){              
      move = changeMove(move);
      makeMove(board, move);  
      displayBoard(board);  
}

Answer 1

From your code provided, it looks like you are already given the board .

It is:

char[] board = {'1', '2', '3', '4', '5', '6', '7', '8', '9'};

What you want to do is turn it in to a 3x3 display.

This could be as simple as:

int k =0;
char[] board = {'1', '2', '3', '4', '5', '6', '7', '8', '9'};
for (int i=1;i<=3;i++) {
    for (int j=1;j<=3;j++) {
        System.out.print(board[k]);
        k++;
    }
System.out.println();
}

I think what is confusing you is thinking that you will have to update the tic-tac-toe logic part of the problem in the display itself.

What you should do, when you make a move, is change whatever needs to be changed in the board array, and then you can redraw the board.

Answer 2

import java.util.Scanner;

public class TicTacToe {
public static void main (String args[]) {  
    char[] board = {'1', '2', '3', '4', '5', '6', '7', '8', '9'};
    char move = 'O';
    displayBoard(board);

while (!checkWinner(board, move)){              
        move = changeMove(move);
        makeMove(board, move);  
        displayBoard(board);  
}
}

public static void displayBoard(char[] b){
    int k = 0;
    for(int i = 0; i <3 ; i++){
        for (int j=0; j<3; j++){
            System.out.print(b[k]); 
            k++;
        }
        System.out.println();
}       
}

public static char changeMove(char m){
    if(m == 'O'){
        return 'X'; 
    }
    else return 'O';
}

public static void makeMove(char[] b, char m){
    boolean valid = false; 
    System.out.println("========== " + m + "'s Move: Enter [1-9] to choose square =========");  
    Scanner s= new Scanner(System.in);
    char square = s.next().charAt(0);
    for(int i=0; i<9; i++){
        if (b[i] == square){
            b[i] = m;
            valid = true;
        }
    }    
    if(!valid){
            System.out.println("Invalid move");
        makeMove(b,m);
    }
}

public static boolean checkWinner(char[] b , char m){   

    //Horizontal
    if(b[0] == b[1] && b[1] == b[2] ){
        System.out.println(b[0] +" Won!");
        return true;
    }
    if(b[3] == b[4] && b[4] == b[5]){
        System.out.println(b[3] +" Won!");
        return true;
}
    if(b[6] == b[7] && b[7] == b[8]){
        System.out.println(b[6] +" Won!");
        return true;
    }

    //Vertical
    if(b[0] == b[3] && b[3] == b[6]){
        System.out.println(b[0] +" Won!");
        return true;
    }
    if(b[1] == b[4] && b[4] == b[7]){
        System.out.println(b[1] +" Won!");
        return true;
    }
    if(b[2] == b[5] && b[4] == b[8]){
        System.out.println(b[2] +" Won!");
            return true;
    }

    //Diagonal
    if(b[0] == b[4] && b[4] == b[8]){
        System.out.println(b[0] +" Won!");
        return true;            
    }
    if(b[2] == b[4] && b[4] == b[6]){
        System.out.println(b[2] +" Won!");
        return true;
    }

    return false;    
}

}

Answer 3

For displayBoard() , you can use nested for loops. The outer loop iterates through each row, and the inner loop prints the three values that belong to the row.

public void displayBoard(char[] board) {
    for(int i = 1, i < 4, i++) {
        for(int j = 1, j < 4, j++) {
            System.out.print(board[(i*j)-1]);
        }
        System.out.println();
    }
}

Let me know if you need additional help.