为什么变量在 Java 代码中只递增一次？

Question

我正在制作一个游戏，玩家 ('P') 从 [0][0] 处的二维破折号数组开始。提示玩家输入数组的大小，然后输入一个动作（左、右、上、下或退出）。输入该操作后，'P' 应该移动 1 个索引。我正在处理我的 moveDown 方法，目前还没有别的。当我键入 "down" 时，它将递增到 theWorld[1][0]，但如果我键入 "down"，它不会再次递增（theWorld[2][0]）。它只是停留在 [1][0]。

这个程序有两个 class，但是我的另一个 class 目前只有 main 方法和 world.userInput 方法，所以我不会包括那个。这是一项正在进行的工作，所以请原谅任何草率的代码、额外的 space 等。这是我目前所拥有的：

    import java.util.Scanner;

class World {

private int characterRow;
private int characterColumn;
private char[][] theWorld; 
char player = 'P';
int playerX = 0;
int playerY = 0;
String userAction;
boolean keepPlaying = true;
boolean outOfBounds;

public World() {

    characterRow = 0;
    characterColumn = 0;


}
public World(int height, int width) {

    this.characterRow = height;
    this.characterColumn = width;

}

public void setHeight(int height) {

    characterRow = height;

}
public void setWidth(int width) {

    characterColumn = width;

}
public void userInput(int height, int width, int x, int y) {
    Scanner input = new Scanner(System.in);


    System.out.print("Enter World width: ");
    width = input.nextInt();
    System.out.print("Enter World height: ");
    height = input.nextInt();

    displayWorld(height, width, x, y);

    input.nextLine();

    while(keepPlaying)
    {
    System.out.print("ACTION > ");
    String action = input.nextLine();

    while(!action.equalsIgnoreCase("exit"))
    {
        keepPlaying = true;
        if(action.equalsIgnoreCase("down") && x > theWorld.length)
        {
          outOfBounds = true;
          System.out.println("You cannot go out of bounds. Try again.");
        }
        else
        break;
    }

    if(action.equalsIgnoreCase("down"))
    {
        moveDown(height, width, x, y, action);

    }
}

public void moveDown(int height, int width, int x, int y, String action) {

      if(x < theWorld.length-1)
      {
      x += 1;
    }
      displayWorld(height, width, x, y);


}

    public void displayWorld(int height, int width, int x, int y) {
    theWorld = new char[height][width];
    for(height = 0; height < theWorld.length; height++)
    {
        for(width = 0; width < theWorld[height].length; width++)
        {

            theWorld[height][width] = '-';
            theWorld[x][y] = player;


            System.out.print(theWorld[height][width] + " ");
        }
        System.out.println();
    }



}//end displayWorld
}//end class

Answer 1

我添加了一个 setPlayerX 方法，并将 moveDown 中的赋值更改为您在此处看到的内容。它现在有效，所以我想通了。

   public void setPlayerX(int x) {
    x = 1;
    playerX = x;
}
    public void moveDown(int height, int width, int x, int y) {
    x++;
    playerX = playerX + x;
    displayWorld(height, width, x, y);

}

为什么变量在 Java 代码中只递增一次？

Why does variable only increment once in Java code?

java

arrays

loops

post-increment

java.util.scanner