Simple Factory

We use Factory design pattern when the object needs to be extended to sub classes. Simply return the object using the factory class.

We are working with an interface here.

Simple Factory

• Abstracts the creation details of the product
• Refers to the newly created object through an interface
• Any new type creation is handed with a chage of code in the factory class and not at the client code

Interface IVehicleChoice

 public interface IVehicleChoice
    {
        string Buy();
    }

Class Car

This implements IVehicleChoice


public class Car : IVehicleChoice
    {
        public string Buy()
        {
            return "Buying Car";
        }
    }

Class Bike

This implements IVehicleChoice


public class Bike : IVehicleChoice
    {
        public string Buy()
        {
            return "Buying Bike";
        }
    }

Factory Class

It doesn't implement IVehicleChoice. It has a choice mehod which return IVehicleChoice. 


public class VehicleFactory
    {
        public static IVehicleChoice Choice(string choice)
        {
            IVehicleChoice myChoice = null;

            if (!string.IsNullOrWhiteSpace(choice))
            {
                if (choice.ToLower() == "car")
                {
                    myChoice = new Car();
                }
                else if (choice.ToLower() == "bike")
                {
                    myChoice = new Bike();
                }
            }

            return myChoice;

        }
    }

Call

static void Main(string[] args)
        {
            //car
            Console.WriteLine(VehicleFactory.Choice("car").Buy());

            //bike
            Console.WriteLine(VehicleFactory.Choice("bike").Buy());

            Console.ReadLine();
        }

Result

Next

• Simple Factory Advance
• Factory Method
• Abstract Factory Method