创建一个对象数组，但找不到符号

Question

我正在用Java在一个小游戏中创建一个玩家数组。有一个名为Players的类和一个名为Game的类。

在Main中，我们扫描两个名称并将它们发送到Game

game.createPlayer(name1, name2);稍后尝试获取
一些信息 playerArray[(game.getPlayerTurn() % 2)].getPlayerName();

Player在Game中构造为数组：

public class Game
{
private Player[] playerArray;
[...]
public void createPlayer(String name1, String name2)
  {
    Player[] playerArray = new Player[2];        
    playerArray[0] = new Player(name2);           
    playerArray[1] = new Player(name1);
  }

将Player作为标准类：

public class Player
{
  private String playerName;
  public Player( String playerName )
  {
    this.playerName = playerName;
  }
  public String getPlayerName()
  {
    return playerName;
  }
}

但是，这会返回多个错误，指出无论我尝试找出玩家名称的何处，它都找不到该符号。我不是没有正确地实例化它们吗？

附加代码(根据要求(：

package oop.nimspiel;
import java.util.Scanner;
import java.util.Arrays;
public class Game
{
  private int take;
  private int turn;
  private int playerTake;
  private int playerTurn;
  protected Player[] playerArray;
  public Game(int turn, int playerTurn)
  {
    this.turn = turn;
    this.playerTurn = playerTurn;
  }
  protected void setPlayerTake(int take)
  {
    this.playerTake = take;
  }
  public int getPlayerTake()
  {
    return playerTake;
  }
  public void incrementTurns()
  {
    turn = turn + 1;
    playerTurn = playerTurn + 1;
  }
  public int getTurn()
  {
    return turn;
  }
  public int getPlayerTurn()
  {
    return playerTurn;
  }
  public void createPlayer(String name1, String name2)
  {
    this.playerArray = new Player[2];
    playerArray[0] = new Player(name2);
    playerArray[1] = new Player(name1);
  }
  public String getPlayer()
  {
    String playerName = playerArray[(getPlayerTurn() % 2)].getPlayerName();
    return playerName;
  }
  public void checkTake(int take)
  {
    Scanner input = new Scanner(System.in);
    this.take = take;
    boolean rightInput = false;
    do {
      if (take < 1 || take > 3)
      {
        System.out.println("Your input was wrong, please use a number between 1 and 3.");
        System.out.println("How many stones would you like to take?");
        take = input.nextInt();
        rightInput = false;
      }
      else if (stoneheap.getStones() < take) {
        System.out.println("There are only " + stoneheap.getStones() + " stones left.");
        System.out.println("Please take less.");
        System.out.println("How many stones would you like to take?");
        take = input.nextInt();
        rightInput = false;
      }
      else
      {
        rightInput = true;
      }
    } while (rightInput == false);
  }
}

和主要：

package oop.nimspiel;
import java.util.Random;
import java.util.Scanner;
import java.util.Arrays;
public class Main
{
  private int take;
  public static void main(String[] args)
  {
    Scanner input = new Scanner(System.in);
    String nextRound;
    do
    {
      int maxPlayers = 2;
      int startTurn = 1;
      Game game = new Game ( startTurn, (1 + (int)(Math.random() * ((maxPlayers - 1) + 1)) ) );
      int minStones = 20;
      int maxStones = 30;
      Stoneheap stoneheap = new Stoneheap((minStones + (int)(Math.random() * ((maxStones - minStones) + 1)) ) );
      System.out.println("Rules: Two players take stones from a heap of 20 to 30 until there are no more left. The one to take the last stone loses. Each round you can only take between 1 - 3 stones. Have fun!");   // Rules
      System.out.println("");
      System.out.println("Hello Player 1, what is your name?");
      String name1 = input.next();
      System.out.println("");
      System.out.println("Hello Player 2, what is your name?");
      String name2 = input.next();
      game.createPlayer(name1, name2);
      System.out.println("");
      System.out.println("Number of stones: " + stoneheap.getStones());
      System.out.println("The first to draw is Player " + game.getPlayerTurn());
      System.out.println("The game starts now!");
      while (stoneheap.getStones() > 0)
      {
        if ((game.getPlayerTurn() % 2) > 0)         // Turn Player 1
        {
          System.out.println("It is your turn " + playerArray[(game.getPlayerTurn() % 2)].getPlayerName() + ".");
          System.out.println("How many stones would you like to take?");
          int take = input.nextInt();
          game.checkTake(take);
          game.setPlayerTake(take);
          stoneheap.currentStones();
          System.out.println("There are  " + stoneheap.getStones() + " stones left.");
        }
        else    // Turn Player 2
        {
          System.out.println("It is your turn " + playerArray[(game.getPlayerTurn() % 2)].getPlayerName() + ".");
          System.out.println("How many stones would you like to take?");
          int take = input.nextInt();
          game.checkTake(take);
          game.setPlayerTake(take);
          stoneheap.currentStones();
          System.out.println("There are  " + stoneheap.getStones() + " stones left.");
        }
        game.incrementTurns();
      }
      System.out.println("The game has ended and the winner is ...");
      System.out.println(playerArray[(game.getPlayerTurn() % 2)].getPlayerName());
      System.out.println("It took " + (game.getTurn() - 1) + " turns." );
      System.out.println("");

      System.out.println("Do you want to play another round? Y for yes, anything else for no");
      String userInput = input.next();
      nextRound = userInput.toUpperCase();
    } while (nextRound.equals("Y"));
  }
}

Answer 1

在createPlayer方法中，您应该通过关键字 ( this.playerArray = new Player[2] ( 访问playerArray this 。

目前，您

正在动态创建一个数组，并且类变量保持不变，这就是您收到异常的原因。

public class Game
{
private Player[] playerArray;
[...]
public void createPlayer(String name1, String name2)
  {
    this.playerArray = new Player[2];        
    playerArray[0] = new Player(name2);           
    playerArray[1] = new Player(name1);
  }