Do While 循环卡住

Question

该代码是一个井字游戏（进行中）。当我运行代码询问 X 的位置编号时，它会停止。它与 while 循环有关，因为当我运行它没有它时它工作正常。但是，我需要循环将 X 设置为 false，以便轮到 O。

import java.util.Scanner;
class TicTacToe


{
public static void main(String[] args)

{
    Scanner scan = new Scanner(System.in);
    int XInput, OInput;
    boolean IfGameOver;
    String []board = {"1","2","3","4","5","6","7","8","9"};
    IfGameOver = false;
    boolean Xturn, Oturn;
    Xturn = true;
    Oturn = false;

    System.out.print("Welcome to Tic-Tac-Toe!\n\n");
do
    {

        {
         System.out.println(" " + board[0] + board[1] + board[2]);
         System.out.println(" " + board[3] + board[4] + board[5]);
         System.out.println(" " + board[6] + board[7] + board[8]);
        }
             if (Xturn)
             System.out.println("It is X's turn, position number?");
             if (Oturn)
             System.out.println("It is O's turn, position number?");

            do
                {
                try
                {
                XInput = scan.nextInt();
                board[XInput-1] = "X";
                Oturn= true;
                Xturn = false;
                }
                catch (NumberFormatException e)
                {
                    System.out.println("Invalid input. Please enter a position number");
                    XInput = scan.nextInt();
                }
                }while(Xturn = true);
            do
                {
                try
                {
                OInput = scan.nextInt();
                board[OInput-1] = "X";
                Oturn = false;
                Xturn = true;
                }
                catch (NumberFormatException e)
                {
                    System.out.println("Invalid input. Please enter a position number");
                    OInput = scan.nextInt();
                }
                }while (Oturn = true);

    } while (!IfGameOver);
}
}

Answer 1

问题可能出在这条线上：

            }while(Xturn = true);

这不是比较。 = 运算符是赋值。这会将值 true 赋值给 Xturn，然后继续循环，因为赋值的结果始终是赋值的值。

为了比较，您可以使用 ==。但是由于 Xturn 是一个布尔值开头，你可以简单地写：

            }while(Xturn);

Answer 2

改变

}while(Xturn = true);
...
}while (Oturn = true);

至

}while(Xturn);
...
}while (Oturn);

Xturn = true 是一项赋值，不会检查 Xturn 是否为真。为此，您必须使用 Xturn == true 或简单的 Xturn。 Oturn.

也是如此

此外，如 TAsk 所述，您需要 IfGameOver 的值在循环内变为真，以便代码退出外部 do while 循环。

Answer 3

您有多个问题。如前所述，您没有在 while 语句中使用相等性检查，但其他问题覆盖了这个问题。您在 X 轮之后但在轮到 O 的 do-while 循环之前将 Oturn 设置为真。因此，您将在 X 输入后立即进入 Oturn do 循环。这应该清理它...

import java.util.Scanner;
class TicTacToe

{
public static void main(String[] args)

{
    Scanner scan = new Scanner(System.in);
    int Input;
    boolean IfGameOver;
    String []board = {"1","2","3","4","5","6","7","8","9"};
    IfGameOver = false;
    boolean Xturn = true;

    System.out.print("Welcome to Tic-Tac-Toe!\n\n");
do
    {

        {
         System.out.println(" " + board[0] + board[1] + board[2]);
         System.out.println(" " + board[3] + board[4] + board[5]);
         System.out.println(" " + board[6] + board[7] + board[8]);
        }
             if (Xturn)
             System.out.println("It is X's turn, position number?");
             else
             System.out.println("It is O's turn, position number?");

             Input = -1;
            do
                {
                try
                {
                Input = scan.nextInt();
                board[Input-1] = (Xturn?"X":"O");
                Xturn = !Xturn;
                }
                catch (Exception e)
                {
                    System.out.println("Invalid input. Please enter a valid position number");
                }
                }while(Input==-1);
    } while (!IfGameOver);
}
}

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