Singleton deisgn pattern in c# Lazy and Eager initialization

In this post we are going to see how to create a singleton class in eager and lazy initialization concepts in c#

Key things to remember for singleton is
1. Private constructor
2. Static Property to get the instance
3. Backing field should be readonly static
4.  Singleton class should be sealed

Lazy Initialization
*************************
First we create lazy initialization of singleton class

public sealed class EmployeeSingleton

    {

        private static readonly Lazy<EmployeeSingleton> _instance = new

                    Lazy<EmployeeSingleton>(() => new EmployeeSingleton());

        private EmployeeSingleton() { }

        public static EmployeeSingleton Instance

        {

            get

            {

                return _instance.Value;

            }

        }

        public void Log(string message)

        {

            Console.WriteLine(message);

        }

    }

Eager Initialization
**************************

    public sealed class DepartmentSingleton

    {

        private static readonly DepartmentSingleton _instance = new

                                             DepartmentSingleton();

        private DepartmentSingleton()

        {

        }

        public static DepartmentSingleton Instance

        {

            get

            {

                return _instance;

            }

        }

        public void Log(string message)

        {

            Console.WriteLine(message);

        }

    }

Main program:
**************

static void Main(string[] args)

        {

            EmployeeSingleton obj1 = EmployeeSingleton.Instance;

            DepartmentSingleton obj2 = DepartmentSingleton.Instance;

            obj1.Log("test 1");

            obj2.Log("test 2");

            Console.Read();

        }

From this post you can learn how to create a singleton design pattern in c# lazy and eager initialization.