我正在嘗試制作一個在命令行上播放的跳棋游戲，我不知道如何根據用戶輸入移動棋子

Question

我的程序將打印出電路板並要求用戶輸入，但輸入不會改變電路板打印出來的內容。 我已將 userInput 分配到相應的位置，但似乎無法使碎片移動。 我只是在學習如何使用不同的方法，我認為這就是我的大部分問題的來源。 電路板打印輸出是一種方法，目前運動是主要方法的一部分。

...

import java.util.Scanner;
public class Checkers {
public static void printBoard () {
    String[][] board = new String [9][9];
    for (int i=0; i < board.length; i++) {
        for (int j=0; j < board[i].length; j++) {
            board[i][j] = "";
        }
    } 
     // Numbers for rows.
    board[1][0] = "2";
    board[2][0] = "3";
    board[3][0] = "4";
    board[4][0] = "5";
    board[5][0] = "6";
    board[6][0] = "7";
    board[7][0] = "8"; 
    
    board[0][1] = "1";// Numbers for columns.
    board[0][2] = "2";
    board[0][3] = "3";
    board[0][4] = "4";
    board[0][5] = "5";
    board[0][6] = "6";
    board[0][7] = "7";
    board[0][8] = "8";
    
    board[8][1] = "WP";
    board[8][3] = "WP";
    board[8][5] = "WP";
    board[8][7] = "WP";
    board[7][2] = "WP";
    board[7][4] = "WP";
    board[7][6] = "WP";
    board[7][8] = "WP";
    board[6][1] = "WP";
    board[6][3] = "WP";
    board[6][5] = "WP";
    board[6][7] = "WP";
    
    board[1][2] = "BP";
    board[1][4] = "BP";
    board[1][6] = "BP";
    board[1][8] = "BP";
    board[2][1] = "BP";
    board[2][3] = "BP";
    board[2][5] = "BP";
    board[2][7] = "BP";
    board[3][2] = "BP";
    board[3][4] = "BP";
    board[3][6] = "BP";
    board[3][8] = "BP";
    
    for (int i=0; i < 1; i++) {
        for (int j=0; j < 9; j++) {
            System.out.print(board[i][j] + "     " );
        }
    }   
    System.out.println();
    
    boolean iswhite = true;
    String emptyBlack = "      ";
    String emptyWhite = "******";
    
    
    for (int i= 1; i< board.length; i++) {
        for (int j= 1; j< board[i].length; j++) {
            if (iswhite) {
                System.out.print(emptyWhite);
            } else {
                System.out.print(emptyBlack);
            }
            iswhite = !iswhite;
        }   
        System.out.println();
        
        for (int j=1; j< board[i].length; j++) {
            if (iswhite) {
                if (board[i][j].equals("")) {
                    System.out.print(emptyWhite);
                }   else {  
                System.out.print("**" + board[i][j] + "**");
                }
            }   else {
                    if (board[i][j].equals("")) {
                        System.out.print(emptyBlack);
                    } else {    
                    System.out.print("  " + board[i][j] + "  ");
                    }
                }   
                iswhite = !iswhite;
        }
        
        System.out.println();
        
        for (int j=1; j< board[i].length; j++) {
            if (iswhite) {
                System.out.print(emptyWhite);
            } else {
                System.out.print(emptyBlack);
            }
            iswhite = !iswhite;
        }   
        System.out.println();
        
        iswhite=!iswhite;
    }
  }

public static void main (String [] args) {
    Scanner scnr = new Scanner(System.in);
    
    System.out.println("Please select a piece to move by entering it's location.");
    
    int playerHz = scnr.nextInt();
    int playerVt = scnr.nextInt();
    System.out.println("Enter a new location.");
    
    int newHz = scnr.nextInt();
    int newVt = scnr.nextInt();
    String[][] board = new String [9][9];
    
    for (int i = 1; i < board.length; i++) {
        for (int j = 1; j <board[i].length; j++) {
            if (board[i][j] == (board[playerHz][playerVt]) ) {
             board[i][j] = "";
            }
            board[newHz][newVt] = "WP";
        }
    }
    printBoard();

 }
    
...
    
    
    
    

}   

Answer 1

變量String[][] board似乎是printBoard和main方法中的局部變量。 一種方法不能影響其范圍之外的局部變量。 換句話說，即使變量在兩種方法中命名相同，它們實際上是不同的變量。 最簡單的解決方案是使String[][] board變量全局化。