Sealed method in C#

Question

I am a newbie in C#.I am reading about Sealed keyword.I have got about sealed class.I have read a line about Sealed method where we can make Sealed method also.The line was

Answer 1

Well, you'd only use "sealed" on a method if you didn't want any derived classes to further override your method. Methods are sealed by default, if they're not declared as virtual and not overriding another virtual method. (In Java, methods are virtual by default - to achieve "default" C# behaviour you have to mark a method as final.)

Personally I like to control inheritance carefully - I prefer whole classes to be sealed where possible. However, in some cases you still want to allow inheritance, but ensure that some methods aren't overridden further. One use might be to effectively template the method, e.g. for diagnostics:

public sealed override void Foo(int x)
{
    Log("Foo called with argument: {0}", x);
    FooImpl(x);
    Log("Foo completed");
}

protected abstract void FooImpl(int x);

Now subclasses can't override Foo directly - they'd have to override FooImpl, so our behaviour will always be executed when other code calls Foo.

The templating could be for other reasons of course - for example to enforce certain aspects of argument validation.

In my experience sealed methods aren't used terribly often, but I'm glad the ability is there. (I just wish classes were sealed by default, but that's another conversation.)