Sealed class and Sealed method in C#.Net

In this post we will discuss about Sealed class and Sealed method in C#.Net.

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Sealed class:
C#.Net allows classes and methods to be declared as sealed. In the case of a class, this means you can’t inherit from that class. If you want no one should extend your class then you can make that class as Sealed class.

To make a class as Sealed we have to use the Sealed keyword.

sealed class MySealedClass
{
// Code will go here
}

Now suppose you want to inherit this class in any other class like below, then it will give a compilation error.

class MyDerivedClass: MySealedClass
{
// Code will go here
}

Sealed Method:
Similarly C#.Net allows us to make methods as Sealed so that no other class can use the method.

sealed class MySealedClass
{
public sealed override void MyMethod()
{
//Code will go here
}
}

But if you try to access the sealed method in the child class then it will give a compailation error.

class MyDerivedClass: MySealedClass
{
public override void MyMethod()
{
//Code will go here
}
}

In order to use the sealed keyword on a method or property, it must have first been overridden from a base class.