java - 如何让计数器在 while 循环中工作？

Question

所以我试着让 int Posx; 保存一个数字，然后当用户浏览菜单时，根据他们的选择，将添加 1、0 或 -1到 int Posx。我无法让 Posx 在加减后保留数字。我正在尝试浏览一个数组，我想保留 2 个整数作为标记，让我知道我目前在数组中的 x 和 y 位置。

tl;dr 如何在 do/while 循环中保留一个计数器？

这里是问题所在:

    //this variable will hold if we found or not the string in the puzzle
    boolean found = true;

    do {    

        //Print out the array
        for (int x = 0; x < maze.length; x++) {
            for (int y = 0; y < maze[0].length; y++) {
                System.out.print(maze[x][y]);
            }
            System.out.println();
        }

        System.out.printf("You may:\n1) Move up\n2) Move down\n3) Move left\n4) Move right\n0) Quit\nYour Choice (0-4):\n");
        int usrAns = sc2.nextInt();

        if (usrAns == 0){
            System.out.println("Bye!\n");
            found = false;
            break;
        }           

        //arrays to hold the direction.
        int[] movx ={ -1,  0, 0, 1};
        int[] movy ={ 0, -1, 1,  0};

        //Array to hold the position. 
        int Posx = 0;
        int Posy = 0;       

        if (usrAns == 1){
            if(check(Posx, Posy, maze, movx[1], movy[1])){
                    System.out.println("Cannot move past cave boundary! Try something else.\n");
                    continue;
                }
                else{
                    Posy = Posy - 1;
                    System.out.printf("This is Posx %d and Posy %d\n", Posx, Posy);
                    continue;
                }
        }
        if (usrAns == 2){
            if(check(Posx, Posy, maze, movx[2], movy[2])){
                    System.out.println("Cannot move past cave boundary! Try something else.\n");
                    continue;
                }
                else{
                    Posy= Posy + 1;
                    System.out.printf("This is Posx %d and Posy %d\n", Posx, Posy);
                    continue;
                }
        }
        if (usrAns == 3){
            if(check(Posx, Posy, maze, movx[0], movy[0])){
                    System.out.println("Cannot move past cave boundary! Try something else.\n");
                    continue;
                }
                else{
                    Posx = Posx - 1;
                    System.out.printf("This is Posx %d and Posy %d\n", Posx, Posy);
                    continue;
                }
        }
        if (usrAns == 4){
            if(check(Posx, Posy, maze, movx[3], movy[3])){
                    System.out.println("Cannot move past cave boundary! Try something else.\n");
                    continue;
                }
                else{
                    Posx =Posx + 1;
                    System.out.printf("This is Posx %d and Posy %d\n", Posx, Posy);
                    continue;
                }
        }
        while (usrAns >= 5 || usrAns < 0){
            System.out.println("Please enter a number between 0 and 4:\n");
            usrAns = sc2.nextInt();
            if (usrAns == 0){
                System.out.println("Bye!\n");
                found = false;
                break;
            }

        }
    }while(found);

如有任何想法、提示或技巧，我们将不胜感激。

Answer 1

我觉得问题出在这两行

    //Array to hold the position. 
    int Posx = 0;
    int Posy = 0;   

您每次迭代都会重置 Posx 和 Posy。尝试将它们设置在 while 循环之外。像这样(你不想一遍又一遍地初始化它们)。 movx 和 movy 相同:

//arrays to hold the direction.
int[] movx ={ -1,  0, 0, 1};
int[] movy ={ 0, -1, 1,  0};

//Array to hold the position. 
int Posx = 0;
int Posy = 0;       

do {
    //Print out the array
    for (int x = 0; x < maze.length; x++) {
    ...
    ...

为了提高代码的可读性，您可以查看 switch statement并尝试松开多个 continue 语句:

    switch(usrAns) {
        case 1:
            if(check(Posx, Posy, maze, movx[1], movy[1])){
                System.out.println("Cannot move past cave boundary! Try something else.\n");
            }
            else{
                Posy = Posy - 1;
                System.out.printf("This is Posx %d and Posy %d\n", Posx, Posy);
            }
            break;
        case 2:
        ...
        ...
        default:
            while (usrAns >= 5 || usrAns < 0){
                System.out.println("Please enter a number between 0 and 4:\n");
                usrAns = sc2.nextInt();
                if (usrAns == 0){
                    System.out.println("Bye!\n");
                    found = false;
                    break;
                }
            }
            break;
         }