What is sealed class in C#? Can anyone give the example?

Question

Need to know class definition? Interface definition ? and distinguish between to of them???

Answer 1

Sealed Class

Sealed class is used to define the inheritance level of a class.

The sealed modifier is used to prevent derivation from a class. An error occurs if a sealed class is specified as the base class of another class.

Some points to remember:

1. A class, which restricts inheritance for security reason is declared, sealed class.
2. Sealed class is the last class in the hierarchy.
3. Sealed class can be a derived class but can't be a base class.
4. A sealed class cannot also be an abstract class. Because abstract class has to provide functionality and here we are
   restricting it to inherit.

Practical demonstration of sealed class

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace sealed_class
{
class Program
{
public sealed class BaseClass
{
public void Display()
{
Console.WriteLine("This is a sealed class which can;t be further inherited");
}
}

    public class Derived : BaseClass
    {
        // this Derived class can;t inherit BaseClass because it is sealed
    }

    static void Main(string[] args)
    {
        BaseClass obj = new BaseClass();

        obj.Display();

        Console.ReadLine();
    }
}

}