如何掃描二維數組？

Question

我正在嘗試讀取文件並將數據填充到二維數組中。 但是在掃描過程中，當我將數據分配到我的MazePoint[][]數組中時。 它給出以下錯誤消息。

Type mismatch: cannot convert from int to MazePoint

代碼塊：

public MazePoint[][] readMaze(String fileToRead) throws IOException
{
    FileInputStream fileByteStream = null; // File input stream
    Scanner inFS= null;                   // Scanner object
    fileByteStream = new FileInputStream(fileToRead);
    inFS= new Scanner(fileByteStream);
    int size = inFS.nextInt();
    MazePoint[][] maze = new MazePoint[size][size];
    while(inFS.hasNext()) {
        for (int row = 0; row < size; row++) {
            for (int column = 0; column < size; column++) {
                maze[row][column] = inFS.nextInt();
            }
        }
    }
    return maze;
}    

謝謝

Answer 1

MazePoint 是一種新型的對象（類）。 因此，您不能在那里分配 integer。 但這是可能的。

1. 在您的 MazePoint class 中，使用getter和setter添加一個新的value屬性。

class MazePoint {
    private int value;
    // ... other things here

    public int getValue() {
        return value;
    }

    public void setValue(int value) {
        this.value = value;
    }
    // ... other things
}

2. 然后使用 setter 方法賦值。

public MazePoint[][] readMaze(String fileToRead) throws Exception
{
    FileInputStream fileByteStream = new FileInputStream(fileToRead);; // File input stream
    Scanner inFS= new Scanner(fileByteStream);                  // Scanner object
    int size = inFS.nextInt();
    MazePoint[][] mazePoints = new MazePoint[size][size];
    while(inFS.hasNext()) {
       for (int row = 0; row < size; row++) {
           for (int column = 0; column < size; column++) {
               mazePoints[row][column] = new MazePoint();
               mazePoints[row][column].setValue(inFS.nextInt());
            }
        }
    }
    return mazePoints;
}

完成（演示）項目：

import java.io.FileInputStream;
import java.util.Scanner;

public class Maze {
    
   public static void main(String[] args) throws Exception {
      Maze maze = new Maze();
      MazePoint[][]  mazePoints = maze.readMaze("twoDarray.txt");
      maze.print(mazePoints);
   }
   
   public MazePoint[][] readMaze(String fileToRead) throws Exception
   {
       FileInputStream fileByteStream = new FileInputStream(fileToRead);; // File input stream
       Scanner inFS= new Scanner(fileByteStream);// Scanner object
       int size = inFS.nextInt();
       MazePoint[][] mazePoints = new MazePoint[size][size];
       while(inFS.hasNext()) {
           for (int row = 0; row < size; row++) {
               for (int column = 0; column < size; column++) {
                   mazePoints[row][column] = new MazePoint();
                   mazePoints[row][column].setValue(inFS.nextInt());
               }
           }
       }
       return mazePoints;
   }
   
   public void print( MazePoint[][] mazePoints) {
       int size = mazePoints.length;
       for (int row = 0; row < size; row++) {
           for (int column = 0; column < size; column++) {
               System.out.print(mazePoints[row][column].getValue() + " ");
           }
           System.out.println();
       }
   }
}

class MazePoint {
    private int value;

    public int getValue() {
        return value;
    }

    public void setValue(int value) {
        this.value = value;
    }
}

輸入文件twoDarray.txt ：

2 1 2 3 4

Output：

1 2
3 4