c# - 如何在 C# 中创建自己的对象，该对象只能具有已定义的有限数量的值，例如像 Haskell 中的 Bools？

Question

在 Haskell 中，您可以创建一个新的数据类型，例如如下所示:

Player = Player1 | Player2

在您的代码中，您可以通过键入 Player1 来检查它是 Player1 还是 Player2，而不是像“Player1”这样的奇怪的东西，它必须是一个字符串或检查一个整数。在 C# 中可能有类似的东西吗？我只能想到:

class Player
{
    public int CurrentPlayer { get; private set; }
    public Player(int plyr)
    {
        CurrentPlayer = plyr;
    }
}

但现在我不能仅使用 thisplayer = Player1 来检查(如果 thisplayer 是玩家)。最终这意味着:如何创建自己的对象，它只能具有已定义的有限数量的值，例如 Bools？

Answer 1

使用Enums :

using System;

public class Program
{
    private enum Player { PlayerOne, PlayerTwo }

    public static void Main()
    {
        Player player = Player.PlayerTwo; // Change me between Player.PlayerOne and Player.PlayerTwo to see the output change.
        switch(player)
        {
            case Player.PlayerOne:
                //this will get executed
                Console.WriteLine("Player is Player One!");
                //do stuff
                break;

            case Player.PlayerTwo:
                //this will not get executed
                Console.WriteLine("Player is Player Two!");
                //do stuff
                break;

            default:
                //this will not get executed
                break;
        }
    }
}

输出:

玩家是玩家二!

See for yourself on .NET Fiddle