Singleton - [Creational Patterns]

Singleton Definition

Ensure a class has only one instance and provide a global point of access to it.

This structural code demonstrates the Singleton pattern which assures only a single instance (the singleton) of the class can be created.

namespace Singleton

{

    class Program

    {

        static void Main(string[] args)

        {

            Singleton s1 = Singleton.Instance();

            Singleton s2 = Singleton.Instance();

            if (s1 == s2)

            {

                Console.WriteLine("Indenticle Instances");

            }

            Console.ReadKey();

        }

    }

}

Singleton Class

namespace Singleton

{

    class Singleton

    {

        public static Singleton _instance;

        protected Singleton()

        {

        }

        public static Singleton Instance()

        {

            if (_instance == null)

            {

                _instance = new Singleton();

            }

            return _instance;

        }

    }

}