C# Online Compiler | .NET Fiddle

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++);
		
	}
}
}

 
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;
    