Question

or am I missing something basic here??..

since sealed method avoids it to be overridden in the derived class and virtual allows it to

Answer 1

1. The virtual keyword will let you (or someone using your code) override a given method with their own logic.

2. The abstract keyword will force you (or someone else using your code) to override it with your own logic.

3. The sealed keyword will let you (or someone using your code) prevent any further modification of a method.

An overriden method can be overriden again if you don’t add “sealed”.

When you think of these keywords, think of both scenarios: you can code for yourself, or you can create DLLs and code libraries for others to use. The latter scenario will often warrant the use of sealed, abstract and virtual.

Hope this helps!