足球队：对象和类

Question

在我发布我的问题之前，我只需要关于如何改进我的 java 程序的指导，因为我想学习。

所以，对于我的任务，我需要：

创建 3 个类，应用程序，足球运动员和足球队。应用程序（应用程序）将使用另外两个类（足球运动员和足球队）。

应用会

• 创建 11 名足球运动员（您可以将他们放在一个数组中或 数组列表）
• 使用上述球员创建一个足球队使用 足球队实例（对象）显示请求的信息 在实验室里

一个足球运动员课

• 至少有 5 个属性来自 您选择返回有关播放器的完整信息的方法

一个足球队课有

• 名字和吉祥物
• 11 名足球运动员
• 任何其他属性（可选）
• 一种显示有关团队的所有信息的方法，包括：
  • 姓名
  • 吉祥物，以及球队中每位球员的信息
  • 一种使用输入参数（例如球员位置或球员编号）显示球队中特定球员信息的方法。例如，来自 A 队，显示有关四分卫的信息，或显示有关 5 号球员的信息。

我对团队课程感到困惑。我不知道如何将 11 个玩家添加到类中并为玩家实例提供输入参数。我不确定我的应用程序类，因为我不知道如何使用足球队实例（对象）来显示实验室中请求的信息。

这是我目前所拥有的

public class app {
public static void main(String[] args)
{
        player pl1 = new player
        ("Christian","Campbell","Cornerback","Alabama","Central");
            System.out.println(pl1.getInfo());

        player pl2 = new player
        ("Marcus","Allen","Safety","Maryland","Dr. Henry A. Wise, Jr");
            System.out.println(pl2.getInfo());
        player pl3 = new player 
        ("Tommy","Stevens","Quarterback","Indiana","Decatur Central");
            System.out.println(pl3.getInfo());
        player pl4 = new player
        ("Nyeem","Wartman-White", "Linebacker","Pennsylvania","Valley View");
             System.out.println(pl4.getInfo());
        player pl5 = new player
        ("George", "Foreman", "Defensive back","Georgia","Parkview");
            System.out.println(pl5.getInfo());
        player pl6 = new player
        ("Andre","Robinson","Right Tackle","Pennsylvania","Bishop McDevitt");
            System.out.println(pl6.getInfo());
        player pl7 = new player
        ("Malik","Golden","Safety","Connecticut","Chesire Academy");
            System.out.println(pl7.getInfo());
        player pl8 = new player
        ("Koa","Farmer","Safety","California","Notre Dame");
            System.out.println(pl8.getInfo());
        player pl9 = new player
        ("Jake","Zembiec","Quarterback","New York","Aquinas Institute");
            System.out.println(pl9.getInfo());
        player pl10 = new player
        ("Brandon","Polk","Wide Receiver","Virgina","Briar Woods");
            System.out.println(pl10.getInfo());
        player pl11 = new player
        ("Trace","McSorley","Quarterback","Virgina","Briar Woods");
            System.out.println(pl11.getInfo());


  }

}

public class player {



//---------Declaring attributes----
    String firstName;
    String lastName;
    String position;
    String State;
    String Highschool;


    player (String inf_firstName, String inf_lastName, String inf_position, String inf_State, String inf_Highschool)
{
            firstName = inf_firstName;
            lastName = inf_lastName;
            position = inf_position;
            State = inf_State;
            Highschool = inf_Highschool;
    }
String getInfo()
{
    return "Name: "+firstName+ " "+lastName+", "+"position: " +position+ ", State: " +State+ ", High School: " +Highschool; 
  }

}

public class team {

   String team = "Penn State";
   String mascot = "Nittany Lions";

    team(String inf_team, String inf_mascot)
      {
        team = inf_team;
        mascot = inf_mascot;                             
      }
team t1 = new team("Penn State", "Nittany Lions");

     String getInfo()
     {
       return "Team Name: "+team+ "Team Mascot: "+mascot;
     }
}

Answer 1

在您的团队类中，在字符串团队和字符串吉祥物下方，您需要一个 player[] 玩家数组。在你的构造函数中，传入一个包含所有玩家的数组。

Answer 2

2 个选项 -

在您的 main 方法中，您创建一个数组并将所有玩家添加到其中，然后将其传递给您的 Team 构造函数，该构造函数将一个内部数组设置为传入数组的值

或者你的 Team 对象有一个类似 addPlayer(player) 的方法，它将玩家添加到你的 Team 的内部玩家数组中。然后在每个玩家创建后调用该方法。

你也应该大写你的类名..比如团队、玩家等。

Answer 3

我没有为实例变量编写getter 或setter 方法，因为我认为您可以弄清楚这些。但从您对Team 类的描述来看，它可能看起来像这样。

public class Team {

    //Instance variables and constants
    private static final int MAX_PLAYERS = 11;
    private Player[] players;
    private String name;
    private String mascot;


    //Constructor
    public Team(String name, String mascot) {
        this.name = name;
        this.mascot = mascot;
        this.players = new Player[MAX_PLAYERS];
    }


    //Add players to the team
    public void addPlayers(List<Player> p) {
        //Ensures only 11 players are added to the team
        for (int i = 0; i < MAX_PLAYERS; i++)
            this.players[i] = p.get(i);
    }

}

为了匹配这个Team 类的实现，你的App 应该更像这样，以便能够将已经构建的List<Player> 传递给addPlayers 类的addPlayers 方法。 ..

public class app {
    public static void main(String[] args) {
        List<Player> players = new ArrayList<>();

        players.add(new Player(/* Parameters for each player object */));
        //Not writing this 11 times!

        Team team = new Team("The Bulldogs", "Bull Dog");
        team.addPlayers(players);
    }
}

Answer 4

由于您有 11 个玩家，最好创建一个对象数组，因为它们具有相似的属性。像这样：

Player[] players = new Player[11];

然后添加它们的参数，然后将它传递给app的构造函数类，它接受一个palyers的列表。

Answer 5

我已更新您的解决方案。这就是您创建类和方法的方式。 请参阅内联 cmets 了解更多信息。希望这会有所帮助。

            public class App {
        public static void main(String[] args) {
            //creating a team
            Team t1 = new Team("Penn State", "Nittany Lions");

            Player pl1 = new Player("Christian", "Campbell", "Cornerback", "Alabama", "Central");
            System.out.println(pl1.getInfo());
            //for example, adding one player to the team t1 created above.

            t1.addPlayer(pl1); 
            //you can repeat this step for adding all the teams

            Player pl2 = new Player("Marcus", "Allen", "Safety", "Maryland", "Dr. Henry A. Wise, Jr");
            System.out.println(pl2.getInfo());
            Player pl3 = new Player("Tommy", "Stevens", "Quarterback", "Indiana", "Decatur Central");
            System.out.println(pl3.getInfo());
            Player pl4 = new Player("Nyeem", "Wartman-White", "Linebacker", "Pennsylvania", "Valley View");
            System.out.println(pl4.getInfo());
            Player pl5 = new Player("George", "Foreman", "Defensive back", "Georgia", "Parkview");
            System.out.println(pl5.getInfo());
            Player pl6 = new Player("Andre", "Robinson", "Right Tackle", "Pennsylvania", "Bishop McDevitt");
            System.out.println(pl6.getInfo());
            Player pl7 = new Player("Malik", "Golden", "Safety", "Connecticut", "Chesire Academy");
            System.out.println(pl7.getInfo());
            Player pl8 = new Player("Koa", "Farmer", "Safety", "California", "Notre Dame");
            System.out.println(pl8.getInfo());
            Player pl9 = new Player("Jake", "Zembiec", "Quarterback", "New York", "Aquinas Institute");
            System.out.println(pl9.getInfo());
            Player pl10 = new Player("Brandon", "Polk", "Wide Receiver", "Virgina", "Briar Woods");
            System.out.println(pl10.getInfo());
            Player pl11 = new Player("Trace", "McSorley", "Quarterback", "Virgina", "Briar Woods");
            System.out.println(pl11.getInfo());

        }

    }

    class Player {

        // ---------Declaring attributes----
        String firstName;
        String lastName;
        String position;
        String State;
        String Highschool;

        Player(String inf_firstName, String inf_lastName, String inf_position, String inf_State, String inf_Highschool) {
            firstName = inf_firstName;
            lastName = inf_lastName;
            position = inf_position;
            State = inf_State;
            Highschool = inf_Highschool;
        }

        String getInfo() {
            return "Name: " + firstName + " " + lastName + ", " + "position: " + position + ", State: " + State
                    + ", High School: " + Highschool;
        }

    }

    class Team {

        String team = "Penn State";
        String mascot = "Nittany Lions";
        Player[] playerArr = new Player[11]; //this is the main part. Array of players (11)
        int playerCount = 0;  //this will track the number of players being added to the team.

        Team(String inf_team, String inf_mascot) {
            team = inf_team;
            mascot = inf_mascot;
        }

        public String getInfo() {
            return "Team Name: " + team + "Team Mascot: " + mascot;
        }

        //Using this method you can add the players to the Player Array.
        public void addPlayer(Player player) {
            if (playerCount < 11) {
                playerArr[playerCount] = player;
                playerCount++;
            }
        }

        //Using this method you find out a player with specific quality 
        //like in this case its position of the player.
        //you can iterate through the Players Array and can find out the player 
        // And after that you can get the information of the player by your method 
        //getInfo
        public String getPlayerInfo(String positionTemp) {
            Player player = null;
            for (int i = 0; i < playerArr.length; i++) {
                if (playerArr[i].position.equals(positionTemp)) {
                    player = playerArr[i];
                    break;
                }
            }
            return player.getInfo();
        }
    }