java - 出现错误 : non-static method getTotalPlayers() cannot be referenced from a static context

Question

我不明白我在这里做错了什么，也不明白这里的任何东西在没有这样声明的情况下如何是静态的。我只需要在这里指出正确的方向。

测试代码:

public class PaintballPlayerTest
{
//Test program for PaintballPlayer assignment

public static void main (String [] args)
{
//Part 1 check constructor & toString --(make sure ID is working too)
PaintballPlayer sheldon = new PaintballPlayer ("Sheldon", "Lee", "Cooper");
PaintballPlayer leonard = new PaintballPlayer ("Leonard", "Hofstadter");
PaintballPlayer amy = new PaintballPlayer ("Amy", "Farrah", "Fowler");

System.out.println(sheldon);
System.out.println(leonard);

//Part 2 test getTotalPlayer --should be 3
System.out.println("The team has this many players " + PaintballPlayer.getTotalPlayers());

我的代码:

import java.util.*;

public class PaintballPlayer
{
private String firstName, middleName, lastName;
private String secFirst, secLast;
private int id;
private int count;
private static int totalPlayers;
private int playerID;
private int players;

public PaintballPlayer(String first, String middle, String last)
{
    count = 0;
    id = totalPlayers++;
    players = count++;
    firstName = first;
    middleName = middle;
    lastName = last;
}

public PaintballPlayer(String f, String l)
{
    this (f,"",l);
    id = count++;


}


 public PaintballPlayer() 
{
totalPlayers++;
 }

 public static int getTotalPlayers() 
{
return totalPlayers;
}

public String toString()
{
    String name;
    String n;
    name = firstName + " " + middleName + " " + lastName;

    return name;

}


public int getPlayerID()
{
    playerID = count;
    return playerID;
}
  }

同样，我的问题出在 getTotalPlayers() 方法上。

编辑:这是我编辑的代码，应用了所提供的修复程序。谢谢!

Answer 1

getTotalPlayers() 不是静态方法，因此您需要 PaintballPlayer 的实例来调用此方法。

如果您想在 PaintballPlayer 中存储玩家总数，您需要一个静态属性(所有实例的引用相同):

class PaintballPlayer {

  private static int totalPlayers;

  public PaintballPlayer() {
    totalPlayers++;
  }

  public static int getTotalPlayers() {
    return totalPlayers;
  }
}