java - switch 语句和用户输入

Question

我正在编写一个程序，用于移动电影《千与千寻》中 Chichiro 的照片。我现在需要做的就是向左、向右、向上、向下移动她。她有一个用户输入的初始位置。然后我的程序要求用户输入来移动她的 u/d/l/r。如何提示用户输入以再次移动她？它总是只会让她感动并退出循环。

// Initial position
Scanner keyboard = new Scanner(System.in);
System.out.print("Starting row: ");
int currentRow = keyboard.nextInt();
System.out.print("Starting column: ");
int currentCol = keyboard.nextInt();

// Create maze
Maze maze = new Maze(numberRows, numberCols, currentRow, currentCol);

System.out.print("Move Chichiro (u/d/lr): ");

char move = keyboard.next().charAt(0);

switch (move){

    case 'u': maze.moveTo(--currentRow, currentCol); // move up 
        break;
    case 'd': maze.moveTo(++currentRow, currentCol); // move down 
        break;
    case 'l': maze.moveTo(currentRow, --currentCol); // move left 
        break;
    case 'r': maze.moveTo(currentRow, ++currentCol); // move right
        break;
    default: System.out.print("That is not a valid direction!");

}

Answer 1

将代码放入 while 循环中，并包含退出方法，例如按 q 键:

 boolean quit=false;

 //keep asking for input until a 'q' is pressed
 while(! quit) {
   System.out.print("Move Chichiro (u/d/l/r/q): ");
   char move = keyboard.next().charAt(0);     

   switch (move){
     case 'u': maze.moveTo(--currentRow, currentCol); // move up
               break;
     case 'd': maze.moveTo(++currentRow, currentCol); // move down break;
     case 'l': maze.moveTo(currentRow, --currentCol); // move left 
               break;
     case 'r': maze.moveTo(currentRow, ++currentCol); // move right
               break;
     case 'q': quit=true; // quit playing
               break;
     default: System.out.print("That is not a valid direction!");}}
  }
}