Question

I have the following piece of code:

if (book.type == A)  do_something();
else if (book.type == B) do_something_else();
....
else do so_some_default_thing.

This code will need to be modified whenever there is a new book type
or when a book type is removed. I know that I can use enums and use a switch
statement. Is there a design pattern that removes this if-then-else?

What are the advantages of such a pattern over using a switch statement?

Answer 1

You could make a different class for each type of book. Each class could implement the same interface, and overload a method to perform the necessary class-specific logic.

I’m not saying that’s necessarily better, but it is an option.