对象数组的未知错误

Question

我正在制作一个玩 pacman 的程序并有几个课程，我有一个 Wall 课程、一个 Goast 课程、一个 Pacman 课程、一个 Pellot 课程和一个 Board 课程。除了板子之外，所有这些都编译没有错误，它不完整但我所拥有的没有编译， 我有的是

import java.awt.*;
import javax.swing.*;
public class Board{
    private int xDim_=1000;
    private int yDim_=900;
    private Pacman pacman_=new Pacman(475,525,0);
    private Goast greenredGoast_=new Goast(525,350,2,Color.RED);
    private Goast onageGoast_=new Goast(525,275,1, Color.ORANGE);
    private Goast pinkGoast_=new Goast(425,350,2,Color.MAGENTA);
    private Goast blueGoast_=new Goast(425,275,0,Color.CYAN);
    Wall[] walls = new Wall[22];
    walls[0]=new Wall(50,850,900,50);  
    walls[1]=new Wall(0,0,50,900);
    walls[2]=new Wall(50,0,900,50);
    walls[3]=new Wall(125,125,50,150);

我在创建新墙的每个条目上都有 100 个错误，错误如下：

 walls[0]=new Wall(50,850,900,50);  
          ^
Board.java:12: error: ';' expected
    walls[0]=new Wall(50,850,900,50);  
           ^
Board.java:12: error: illegal start of type
    walls[0]=new Wall(50,850,900,50);  
            ^
Board.java:12: error: <identifier> expected
    walls[0]=new Wall(50,850,900,50);  
             ^
Board.java:12: error: ';' expected
    walls[0]=new Wall(50,850,900,50);  
                ^
Board.java:12: error: illegal start of type
    walls[0]=new Wall(50,850,900,50);  
                     ^
Board.java:12: error: <identifier> expected
    walls[0]=new Wall(50,850,900,50);  
                      ^
Board.java:12: error: <identifier> expected
    walls[0]=new Wall(50,850,900,50);  
                         ^
Board.java:12: error: illegal start of type
    walls[0]=new Wall(50,850,900,50);  
                            ^
Board.java:12: error: <identifier> expected
    walls[0]=new Wall(50,850,900,50);  
                             ^
Board.java:12: error: <identifier> expected
    walls[0]=new Wall(50,850,900,50);  
                                 ^
Board.java:12: error: illegal start of type
    walls[0]=new Wall(50,850,900,50);  
                                   ^
Board.java:12: error: <identifier> expected
    walls[0]=new Wall(50,850,900,50);  
                                    ^
Board.java:12: error: ';' expected
    walls[0]=new Wall(50,850,900,50);  
                                     ^

我为每一面墙都做到了这一点。我不知道出了什么问题有人请帮忙！！谢谢

Answer 1

您不能在类级别调用walls[0]=new Wall(50,850,900,50);。

public class Board{
    ...
    Wall[] walls = new Wall[22];
    walls[0]=new Wall(50,850,900,50);
    walls[1]=new Wall(0,0,50,900);
    ...
}

您需要将其放置在以下任一位置：

初始化块,

public class Board{
    ...
    Wall[] walls = new Wall[22];
    {
        walls[0]=new Wall(50,850,900,50);
        walls[1]=new Wall(0,0,50,900);
        ...
    }
    ...
}

构造函数

public class Board{
    ...
    Wall[] walls = new Wall[22];

    public Board(){
        walls[0]=new Wall(50,850,900,50);
        walls[1]=new Wall(0,0,50,900);
        ...
    }
    ...
}

或一些方法

public class Board{
    ...
    Wall[] walls = new Wall[22];

    public void fillBoard(){
        walls[0]=new Wall(50,850,900,50);
        walls[1]=new Wall(0,0,50,900);
        ...
    }
    ...
}

Answer 2

假设您只需要一个墙数组，那么我可能会使用静态块来初始化我的墙数组，就像这样 -

private static Wall[] walls = new Wall[22];

static {
  walls[0]=new Wall(50,850,900,50);  
  walls[1]=new Wall(0,0,50,900);
  walls[2]=new Wall(50,0,900,50);
  walls[3]=new Wall(125,125,50,150);
  ...
}

Answer 3

创建一个方法并将您的数组代码放入其中 以下代码将起作用

import java.awt.*;
import javax.swing.*;
public class Board{
    private int xDim_=1000;
    private int yDim_=900;
    private Pacman pacman_=new Pacman(475,525,0);
    private Goast greenredGoast_=new Goast(525,350,2,Color.RED);
    private Goast onageGoast_=new Goast(525,275,1, Color.ORANGE);
    private Goast pinkGoast_=new Goast(425,350,2,Color.MAGENTA);
    private Goast blueGoast_=new Goast(425,275,0,Color.CYAN);

    public void run() { // create a method
    Wall[] walls = new Wall[22];
    walls[0]=new Wall(50,850,900,50);  
    walls[1]=new Wall(0,0,50,900);
    walls[2]=new Wall(50,0,900,50);
    walls[3]=new Wall(125,125,50,150);
    }
}