C# Online Compiler | .NET Fiddle

// Author : Tech Point Fundamentals
// Website : www.techpointfunda.com
// Demo : Sealed Class, Sealed Method in C#

using System;				

// Normal Base Class
public class BaseClass
{
	// Virtual Method
	public virtual void Display()
	{
		Console.WriteLine("Base Class Display() Method is Called");
	}	
	// Virtual Method
	public virtual void Print()
	{
		Console.WriteLine("Base Class Print() Method is Called");
	}
}

// Normal Derived Class
public class ChildClass : BaseClass
{
	// Overriding base class virtual method 
	public override void Display()
	{
		Console.WriteLine("Child Class Overridden Display() Method is Called");
	}	
	// Sealed Method
	public override sealed void Print()
	{
		Console.WriteLine("Child Class Sealed Print() Method is Called");
	}
}

// Sealed Derived Class
public sealed class DerivedClass : ChildClass
{
	// Constructor of sealed class
	public DerivedClass()
	{
		Console.WriteLine("Sealed Derived class Constructor is Called");
	}
	// Sealed Method
	public sealed override void Display()
	{
		Console.WriteLine("Derived Class Sealed Display() Method is Called");
	}	
	// Print() method of ChildClass cannot be Overridden anymore because it is sealed	
	
	// Destructor of sealed class
	~DerivedClass()
	{
		Console.WriteLine("Sealed Derived class Destructor is Called");
	}
}

// Interface having virtual and sealed methods
public interface IBaseInterface
{
	public virtual void Display()
	{
		Console.WriteLine("IBaseInterface Display() Method is Called");
	}
	public sealed void Print()
	{
		Console.WriteLine("IBaseInterface sealed Print() Method is Called");
	}
}

public interface IDerivedInterface : IBaseInterface
{
	void IBaseInterface.Display()
	{
		Console.WriteLine("IDerivedInterface overridden Display() Method is Called");
	}	
}

public class MyClass : IDerivedInterface
{
}

public class Program
{
	public static void Main()
	{
		Console.WriteLine("\n---------- Base Class --------\n");
		BaseClass _baseClass = new BaseClass();
		_baseClass.Display();
		_baseClass.Print();
		
		Console.WriteLine("\n---------- Child Class --------\n");
		ChildClass _childClass = new ChildClass();
		_childClass.Display();
		_childClass.Print();	
		
		Console.WriteLine("\n---------- Sealed Derived Class --------\n");
		DerivedClass _derivedClass = new DerivedClass();
		_derivedClass.Display();
		_derivedClass.Print();			
		
		Console.WriteLine("\n---------- Interface Sealed Method --------\n");
		MyClass _myClass = new MyClass();
		((IDerivedInterface)_myClass).Display();
		((IDerivedInterface)_myClass).Print();
		
		((IBaseInterface)_myClass).Display();
		((IBaseInterface)_myClass).Print();
	}
}

 
// Author : Tech Point Fundamentals
// Website : www.techpointfunda.com
// Demo : Sealed Class, Sealed Method in C#
​
using System;               
​
// Normal Base Class
public class BaseClass
{
    // Virtual Method
    public virtual void Display()
    {
        Console.WriteLine("Base Class Display() Method is Called");
    }   
    // Virtual Method
    public virtual void Print()
    {
        Console.WriteLine("Base Class Print() Method is Called");
    }
}
​
// Normal Derived Class
public class ChildClass : BaseClass
{