java - 通过 for 循环显示 Arraylist 中对象的各个元素？

Question

我正在尝试显示我创建的对象的各个元素。

这是一个简单的 Java 程序，允许用户添加和跟踪玩家详细信息。

在添加详细信息后显示详细信息时，我感到很困惑。这是我的代码的样子

使用案例 2，我可以创建对象并将其输入到 arraylist 中没有问题，但是当我尝试打印它时，我想做类似的事情

System.out.println("Player Name" + myPlayersArrayList.PlayerName + "Player Position" + myPlayerArrayList.PlayerPosition + "Player Age" + "Player Age");

我知道那是不正确的，但我真的不知道该怎么做，如果有人能提供任何帮助，我将不胜感激。谢谢

System.out.println("Welcome to the Football Player database");
 System.out.print(System.getProperty("line.separator"));


     UserInput myFirstUserInput = new UserInput();
    int selection;
            ArrayList<Player> myPlayersArrayList = new ArrayList<Player>();

            while (true) {

                System.out.println("1. View The Players");
                System.out.println("2. Add A Player");
                System.out.println("3. Edit A Player");
                System.out.println("4. Delete A Player");
                System.out.println("5. Exit ") ;
                System.out.print(System.getProperty("line.separator"));

                selection = myFirstUserInput.getInt("Please select an option");
                System.out.print(System.getProperty("line.separator"));
                switch(selection){


        case 1: 

                        if (myPlayersArrayList.isEmpty())
                                    {
                        System.out.println("No Players Have Been Entered Yet");
                        System.out.print(System.getProperty("line.separator"));
                        break;}

                        else 
                        {for(int i = 0; i < myPlayersArrayList.size(); i++){
                            System.out.println(myPlayersArrayList);

        }
                    break;

                    case 2:  {

                        String playerName,playerPos;
                        int playerAge;

                                playerName = (myFirstUserInput.getString("Enter Player name"));
                                playerPos = (myFirstUserInput.getString("Enter Player Position"));
                                playerAge = (myFirstUserInput.getInt("Enter Player Age"));   

                                myPlayersArrayList.add(new Player(playerName, playerPos, playerAge));   ;
                                                        break;
                    }

Answer 1

您需要使用索引来访问单个元素:-

for(int i = 0; i < myPlayersArrayList.size(); i++){
    System.out.println(myPlayersArrayList.get(i));
}

然后你可以在你的Player类中覆盖toString()方法

public String toString() {
    return playerName + " : " + playerAge + " : " + playerPosition;
}