using System;

namespace Crational.Singleton

{

public class Program

{

    public static void Main()

    {

        for ( int i = 0; i < 20; i++ )

        {

              singleton.instance().sgMethod();

              //singletonEarly.instance().sgMethod();

        }

    }

} 

​

public class singleton

{

    // Below implementatio of SingleTon design pattern with lazy load, however it is NOT thread safe, However you can proetct with  lock()  

    private static singleton _instance;

    private static object mylock = new Object();

    private static int n = 0;

    private singleton() {}

    public static singleton instance()

    {

        lock(mylock)

        {

        if( _instance == null )

        {

            _instance = new singleton();

             n = 1;

        }

        }

        return _instance;

    }

    public void sgMethod()

    {

        Console.WriteLine("I am in Singleton method -> " + n++);

    }

}

public class singletonEarly

{

    // Beolow implementatio of SingleTon design pattern with Early load, it is fully thread safe. .Net gaurantees thead safety for Static Initialization    

    private static singletonEarly _instance = new singletonEarly();

    private static int n = 0;

    private singletonEarly() {}

    public static singletonEarly instance()

    {

        return _instance;

    }

    public void sgMethod()

    {

        Console.WriteLine("I am in SingletonEarly method -> " + n++);

    }

}

}

​

​

​

​