C# Online Compiler | .NET Fiddle

// abstract product
public abstract class Card { }

// abstract product
public abstract class Deck { }

// product
public class BicycleCard : Card { }

// product
public class BeeCard : Card { }

// product 
public class BicycleDeck : Deck { }

// product
public class BeeDeck : Deck { }

// concrete factory
public class BicycleCardFactory : CardFactory
{
	public override Card CreateCard()
	{
		return new BicycleCard();
	}
	
	public override Deck CreateDeck()
	{
		return new BicycleDeck();
	}
}

// concrete factory
public class BeeCardFactory : CardFactory
{
	public override Card CreateCard()
	{
		return new BeeCard();
	}
	
	public override Deck CreateDeck()
	{
		return new BeeDeck();
	}
}

// abstract factory
public abstract class CardFactory
{
	public abstract Card CreateCard();
	public abstract Deck CreateDeck();
}

public class Program
{
	public static void Main()
	{
		DoWork(new BicycleCardFactory());
		DoWork(new BeeCardFactory());
	}
	
	// the client depends only on the `CardFactory`
	public static void DoWork(CardFactory cardFactory)
	{
		System.Console.WriteLine("Doing work"); 
		
		var card = cardFactory.CreateCard();
		System.Console.WriteLine("- " + card);
		
		var deck = cardFactory.CreateDeck();
		System.Console.WriteLine("- " + deck);
	}
}

    public static void DoWork(CardFactory cardFactory)
 
// abstract product
public abstract class Card { }
​
// abstract product
public abstract class Deck { }
​
// product
public class BicycleCard : Card { }
​
// product
public class BeeCard : Card { }
​
// product 
public class BicycleDeck : Deck { }
​
// product
public class BeeDeck : Deck { }
​
// concrete factory
public class BicycleCardFactory : CardFactory
{
    public override Card CreateCard()
    {
        return new BicycleCard();

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