public class TicTacToe 
{

	//===================================================================================
    //This function holds the main game loop for Tic Tac Toe.
	//===================================================================================
	
	public static void main(String[] args)
	{

        String v1 = " ";
        String v2 = " ";
        String v3 = " ";
        String v4 = " ";
        String v5 = " ";
        String v6 = " ";
        String v7 = " ";
        String v8 = " ";
        String v9 = " ";
        
        String turn = "X";

		displayBoard(v1, v2, v3, v4, v5, v6, v7, v8, v9);
        
		while(true)  
		{

			int choice = humanPlayerTurn();
			
			if (choice == 1)
			{
				v1 = turn;
			}
			else if  (choice == 2)
			{
				v2 = turn;
			}
			else if (choice == 3)
			{
				v3 = turn;
			}
			else if (choice == 4)
			{
				v4 = turn;
			}
			else if (choice == 5)
			{
				v5 = turn;
			}
			else if (choice == 6)
			{
				v6 = turn;
			}
			else if (choice == 7)
			{
				v7 = turn;
			}
			else if (choice == 8)
			{
				v8 = turn;
			}
			else if (choice == 9)
			{
				v9 = turn;
			}

			displayBoard(v1, v2, v3, v4, v5, v6, v7, v8, v9);

			turn = swapTurn(turn);

		}  //end of while loop

	}
	
	//===================================================================================
    //This function gets the 9 board values and displays them and the board to screen.
	//===================================================================================

	public static void displayBoard(String s1, String s2, String s3, String s4, String s5, String s6, String s7, String s8, String s9)
	{
		System.out.println("   *   *   ");
		System.out.println(" " + s1 + " * " + s2 + " * " + s3 + " ");
		System.out.println("   *   *   ");
		System.out.println("***********");

		System.out.println("   *   *   ");
		System.out.println(" " + s4 + " * " + s5 + " * " + s6 + " ");
		System.out.println("   *   *   ");
		System.out.println("***********");

		System.out.println("   *   *   ");
		System.out.println(" " + s7 + " * " + s8 + " * " + s9 + " ");
		System.out.println("   *   *   ");
		
	}

	//===================================================================================
    //This function asks the human (via screen) to choose a square and returns that value.
	//No checking whether the value is legal or if that square is taken.
	//===================================================================================
	
	public static int humanPlayerTurn()
	{
		Scanner scr = new Scanner(System.in);
		System.out.println("Where do you want to go?");
		int myChoice = scr.nextInt();
		return myChoice;
		
	}
	
	//===================================================================================
    //This function simply returns the opposite of the currentTurn.  So if it is "X", this
	//function returns "O".  If it is "O", this function returns "X".
	//===================================================================================
	
	public static String swapTurn(String currentTurn)
	{
		String nextTurn;
		if (currentTurn.equals("X"))
		{
			nextTurn = "O";
		}
		else  //if (currentTurn.equals("O"))
		{
			nextTurn = "X";
		}	
		return nextTurn;
	}

	//===================================================================================
	
}