向地图添加额外内容答案

【问题标题】：adding extra to a Map向地图添加额外内容
【发布时间】：2021-06-16 09:55:49
【问题描述】：

您好，我正在尝试重新创建足球锦标赛，并且能够使用地图创建组，但现在想将积分添加到每个国家/地区。有人有什么好主意吗？请看看我已经做了什么。

import java.util.*;

class EuroGroupStages {
    
    public static void main(String args[]) {

         Map<String, Set<String>> groupA;
         
//public EuroGroupStages() 
//  {
         groupA = new TreeMap<>();

//  }
         
//public void addCountries(String aGroup)
//  {
        Scanner keyboard = new Scanner(System.in);
        String aCountry, aGroup;
        char anAnswer;
        boolean flag = true;
        
        while(flag)
        {
            Set<String> country = new HashSet<>();
            
            System.out.print("Please enter the group name (A-D):");     
            aGroup = keyboard.next();
        
                for(int i = 1; i < 5; i++)
                {
                    System.out.print("Please enter a country");
                    aCountry = keyboard.next();
                    country.add(aCountry);
                    
                }

            System.out.print("Do you want to continue? Y/N");
            anAnswer = keyboard.findWithinHorizon(".", 0).charAt(0);
                
                if(anAnswer == 'N' || anAnswer == 'n')
                {
                    flag = false;
                }
            groupA.put(aGroup, country);
        }

        System.out.println(groupA);
        
        
        keyboard.close();
//  }

    }
}

【问题讨论】：

标签： java class methods collections maps

【解决方案1】：

我猜你最好创建Group 和Team 类。然后每个Group 将包含Set/List/...（最适合的）Team 对象。

在Team 类中，您可以提供一个包含该团队在小组赛阶段得分的属性。

为您的Group：

public class Group {
    private String name;
    private Set<Team> teams;

    public Group(String name) {
        this.name = name;
        this.teams = new TreeSet<>();
    }

    public void addTeam(Team team) {
        teams.add(team);
    }
}

为您的Team：

public class Team {
    private String name;
    private int points;

    public Team(String name) {
        this.name = name;
    }

    public void addPoints(int amount) {
        this.points += amount;
    }
}

使用示例：

public class EuroGroupStages {
    public static void main(String[] args) {
        // Create group B
        Group groupB = new Group("B");

        // Create teams in group B
        Team belgium = new Team("Belgium");
        Team finland = new Team("Finland");
        Team denmark = new Team("Denmark");
        Team russia = new Team("Russia");

        // Add teams of group B to group B
        groupB.addTeam(belgium);
        groupB.addTeam(finland);
        groupB.addTeam(denmark);
        groupB.addTeam(russia);

        // First matches were played, Belgium and Finland won
        belgium.addPoints(3);
        finland.addPoints(3);
    }
}

注意：我没有运行此代码，它是即时编写的，但应该能让您了解如何解决您的问题。

【讨论】：