如果满足并激活了条件，则不进行雕版印刷 我理解这是一个常见问题，我在C++和Python上看到过，但似乎找不到解释来解决java问题。

附件是我的程序代码，相当长，因为我还是一个新手，正在学习如何简化它

import java.util.Scanner;

public class TicTacToe {
    public static void main(String[] args) {
    boolean gameActive = true;
    boolean player1turn = true;
    String board[][]= {{" ","|"," ","|"," "},{"-","-","-","-","-",},{" ","|"," ","|"," "},{"-","-","-","-","-",},{" ","|"," ","|"," "}};

    commands();
    printBoard(board);

    while (gameActive == true) {
        if (player1turn == true) {
            System.out.println("\nPlayer 1, noughts turn. Please choose a position.");
        } else {
            System.out.println("\nPlayer 2, crosses turn. Please choose a position.");
        }
        String position = null;

        while ("retry".equals(changePosition(position, player1turn, board))) { 
            Scanner keyboard = new Scanner (System.in);
            position = keyboard.nextLine();

            if ("help".equalsIgnoreCase(position)) {
                commands();
            }
            else if ("turn".equalsIgnoreCase(position)){
                turn(player1turn);
            }
            else if ("board".equalsIgnoreCase(position)){
                printBoard(board);
            }
            else {
                 if (!"retry".equalsIgnoreCase(changePosition(position, player1turn, board))) {
                     System.out.println(changePosition(position, player1turn, board));
                     if (player1turn == true) {
                         player1turn = false;
                     }
                     else if (player1turn == false) {
                         player1turn = true;
                     }
                 }
            }
        }
    }
}

public static void commands() {
    System.out.println("\nPlayer 1 is noughts, O");
    System.out.println("Player 2 is crosses, X");
    System.out.println("\nThe board uses a grid format");
    System.out.println("\"A1\" is the top-left position");
    System.out.println("\"A2\" is the top-middle position");
    System.out.println("\"A3\" is the top-right position");
    System.out.println("\"B1\" is the middle-left position");
    System.out.println("\"B2\" is the middle position");
    System.out.println("\"B3\" is the middle-right position");
    System.out.println("\"C1\" is the bottom-left position");
    System.out.println("\"C2\" is the bottom-middle position");
    System.out.println("\"C3\" is the bottom-right position");
    System.out.println("\n\"help\" will reveal this help message");
    System.out.println("\"board\" will reveal the board");
    System.out.println("\"turn\" will reveal whos turn it is");
}

public static void turn(boolean player1turn) {
    if (player1turn == true) {
        System.out.println("\nPlayer 1, noughts turn.");
    } else {
        System.out.println("\nPlayer 2, crosses turn.");
    }
}

public static void printBoard(String[][] board) {
    System.out.print("\n");
    for (int x=0;x<5;x++) {
        for (int y=0;y<5;y++) {
            System.out.print(board[x][y]+"");
        }
        System.out.println();
    }
}

public static String changePosition(String position, boolean player1turn, String[][] board) {
    if (("A1".equalsIgnoreCase(position)) && (player1turn == true)) {
        if (" ".equals(board[0][0])) {
            board[0][0] = "O";
            return board[0][0];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else if (("B1".equalsIgnoreCase(position)) && (player1turn == true)) {
        if (" ".equals(board[2][0])) {
            board[2][0] = "O";
            return board[2][0];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else if (("C1".equalsIgnoreCase(position)) && (player1turn == true)) {
        if (" ".equals(board[4][0])) {
            board[4][0] = "O";
            return board[4][0];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else if (("A2".equalsIgnoreCase(position)) && (player1turn == true)) {
        if (" ".equals(board[0][2])) {
            board[0][2] = "O";
            return board[0][2];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else if (("B2".equalsIgnoreCase(position)) && (player1turn == true)) {
        if (" ".equals(board[2][2])) {
            board[2][2] = "O";
            return board[2][2];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else if (("C2".equalsIgnoreCase(position)) && (player1turn == true)) {
        if (" ".equals(board[4][2])) {
            board[4][2] = "O";
            return board[4][2];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
     else if (("A3".equalsIgnoreCase(position)) && (player1turn == true)) {
        if (" ".equals(board[0][4])) {
            board[0][4] = "O";
            return board[0][4];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else if (("B3".equalsIgnoreCase(position)) && (player1turn == true)) {
        if (" ".equals(board[2][4])) {
            board[2][4] = "O";
            return board[2][4];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else if (("C3".equalsIgnoreCase(position)) && (player1turn == true)) {
        if (" ".equals(board[4][4])) {
            board[4][4] = "O";
            return board[4][4];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else if (("A1".equalsIgnoreCase(position)) && (player1turn == false)) {
        if (" ".equals(board[0][0])) {
            board[0][0] = "X";
            return board[0][0];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else if (("B1".equalsIgnoreCase(position)) && (player1turn == false)) {
        if (" ".equals(board[2][0])) {
            board[2][0] = "X";
            return board[2][0];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else if (("C1".equalsIgnoreCase(position)) && (player1turn == false)) {
        if (" ".equals(board[4][0])) {
            board[4][0] = "X";
            return board[4][0];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else if (("A2".equalsIgnoreCase(position)) && (player1turn == false)) {
        if (" ".equals(board[0][2])) {
            board[0][2] = "X";
            return board[0][2];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else if (("B2".equalsIgnoreCase(position)) && (player1turn == false)) {
        if (" ".equals(board[2][2])) {
            board[2][2] = "X";
            return board[2][2];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else if (("C2".equalsIgnoreCase(position)) && (player1turn == false)) {
        if (" ".equals(board[4][2])) {
            board[4][2] = "X";
            return board[4][2];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
     else if (("A3".equalsIgnoreCase(position)) && (player1turn == false)) {
        if (" ".equals(board[0][4])) {
            board[0][4] = "X";
            return board[0][4];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else if (("B3".equalsIgnoreCase(position)) && (player1turn == false)) {
        if (" ".equals(board[2][5])) {
            board[2][4] = "X";
            return board[2][4];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else if (("C3".equalsIgnoreCase(position)) && (player1turn == false)) {
        if (" ".equals(board[4][4])) {
            board[4][4] = "X";
            return board[4][4];
        } else {
            System.out.println("That spot is taken please choose another place");
            return "retry";
        }
    }
    else {
        if ((position == null) || ("help".equalsIgnoreCase(position)) || ("turn".equalsIgnoreCase(position)) || ("board".equalsIgnoreCase(position))) {
            return "retry";
        } else {
            System.out.println("Error please enter a valid position found by entering \"help\" ");
            return "retry";
        }
    }
}
}

这让我感到困惑，因为似乎if块实际上被触发，并导致线路板[0][0]被更改，但出于某种原因，必须移动到else块，将消息打印到控制台并返回“重试”

我曾尝试将if块中的返回值更改为标准字符串，如“success”，但这似乎无法解决问题。此外，当我将鼠标悬停在返回类型上时，IDE会将它们标识为返回点。我已经确定（我有信心）我使用了正确的语法

我想这是我冗长的代码的一个问题，我相信这对你们所有人来说都是一个问题

---

谢谢。

问题在于，在该循环的每次迭代中，您多次调用您的

changePosition

方法：

while ("retry".equals(changePosition(position, player1turn, board))) { 
        Scanner keyboard = new Scanner (System.in);
        position = keyboard.nextLine();

        if ("help".equalsIgnoreCase(position)) {
            commands();
        }
        else if ("turn".equalsIgnoreCase(position)){
            turn(player1turn);
        }
        else if ("board".equalsIgnoreCase(position)){
            printBoard(board);
        }
        else {
             if (!"retry".equalsIgnoreCase(changePosition(position, player1turn, board))) {
                 System.out.println(changePosition(position, player1turn, board));
                 if (player1turn == true) {
                     player1turn = false;
                 }
                 else if (player1turn == false) {
                     player1turn = true;
                 }
             }
        }
    }
}

首先，在

while

循环的条件下调用它：

while（“重试”。等于（更改位置（位置、播放者1转、棋盘）））

但是，由于参数位置在开始时仍然为空，因此它将简单地返回

“retry”

，并在第一次出现时进入循环

输入职位后，在此处调用该方法：

如果（！“重试”）.equalsIgnoreCase（改变位置）（位置，播放器1转， （董事会）

如果spot是空闲的，它将工作并且不返回“retry”，因此进入

if

语句块。这就是你的情况，从那一刻起，A1就被填满了

然后在下一行中立即再次调用该方法：

系统输出打印LN（改变位置（位置、播放器1转、板））

但由于现在A1已被占用，因此这一次将输出错误“该点已被占用，请选择其他位置”，并返回

“重试”

，您也将打印该错误

然后，在下一次迭代开始时再次检查循环条件时，再次调用该方法。由于您现在使用相同的参数第三次调用它，它将再次输出错误并返回

“retry”

作为返回值，以便再次进入循环

解决方案是每次迭代只调用函数一次，并保存返回值并使用它。 您还应该使用do while循环，因为它应该始终至少运行一次：

String changePositionResult = null;
do {
    final Scanner keyboard = new Scanner(System.in);
    position = keyboard.nextLine();

    if ("help".equalsIgnoreCase(position)) {
        commands();
    } else if ("turn".equalsIgnoreCase(position)) {
        turn(player1turn);
    } else if ("board".equalsIgnoreCase(position)) {
        printBoard(board);
    } else {
        changePositionResult = changePosition(position, player1turn, board);
        if (!"retry".equalsIgnoreCase(changePositionResult)) {
            System.out.println(changePositionResult);
            if (player1turn == true) {
                player1turn = false;
            } else if (player1turn == false) {
                player1turn = true;
            }
        }
    }
} while ("retry".equals(changePositionResult));

String changePositionResult = null;
do {
    final Scanner keyboard = new Scanner(System.in);
    position = keyboard.nextLine();

    if ("help".equalsIgnoreCase(position)) {
        commands();
    } else if ("turn".equalsIgnoreCase(position)) {
        turn(player1turn);
    } else if ("board".equalsIgnoreCase(position)) {
        printBoard(board);
    } else {
        changePositionResult = changePosition(position, player1turn, board);
        if (!"retry".equalsIgnoreCase(changePositionResult)) {
            System.out.println(changePositionResult);
            if (player1turn == true) {
                player1turn = false;
            } else if (player1turn == false) {
                player1turn = true;
            }
        }
    }
} while ("retry".equals(changePositionResult));