This real-world code demonstrates the creation of different animal worlds for a computer game using different factories. Although the animals created by the Continent factories are different, the interactions among the animals remain the same.

// Abstract Factory pattern -- Real World example

using System; namespace DoFactory.GangOfFour.Abstract.RealWorld {   // MainApp test application   class MainApp   {     public static void Main()     {       // Create and run the Africa animal world       ContinentFactory africa = new AfricaFactory();       AnimalWorld world = new AnimalWorld(africa);       world.RunFoodChain();       // Create and run the America animal world       ContinentFactory america = new AmericaFactory();       world = new AnimalWorld(america);       world.RunFoodChain();       // Wait for user input       Console.Read();     }   }   // "AbstractFactory"   abstract class ContinentFactory   {     public abstract Herbivore CreateHerbivore();     public abstract Carnivore CreateCarnivore();   }   // "ConcreteFactory1"   class AfricaFactory : ContinentFactory   {     public override Herbivore CreateHerbivore()     {       return new Wildebeest();     }     public override Carnivore CreateCarnivore()     {       return new Lion();     }   }   // "ConcreteFactory2"   class AmericaFactory : ContinentFactory   {     public override Herbivore CreateHerbivore()     {       return new Bison();     }     public override Carnivore CreateCarnivore()     {       return new Wolf();     }   }   // "AbstractProductA"   abstract class Herbivore   {   }   // "AbstractProductB"   abstract class Carnivore   {     public abstract void Eat(Herbivore h);   }   // "ProductA1"   class Wildebeest : Herbivore   {   }   // "ProductB1"   class Lion : Carnivore   {     public override void Eat(Herbivore h)     {       // Eat Wildebeest       Console.WriteLine(this.GetType().Name +         " eats " + h.GetType().Name);     }   }   // "ProductA2"   class Bison : Herbivore   {   }   // "ProductB2"   class Wolf : Carnivore   {     public override void Eat(Herbivore h)     {       // Eat Bison       Console.WriteLine(this.GetType().Name +         " eats " + h.GetType().Name);     }   }   // "Client"   class AnimalWorld   {     private Herbivore herbivore;     private Carnivore carnivore;     // Constructor     public AnimalWorld(ContinentFactory factory)     {       carnivore = factory.CreateCarnivore();       herbivore = factory.CreateHerbivore();     }     public void RunFoodChain()     {       carnivore.Eat(herbivore);     }   } }

Output Lion eats Wildebeest Wolf eats Bison