Visual Basic 4 introduced the concept of object-oriented programming using the Basic language. Visual Basic 5 takes this concept and elaborates on it in several ways. It is still possible to write Visual Basic 5 code that looks almost exactly like Visual Basic 3 code or that even resembles procedural COBOL code if you want to be committed to an institution for the very silly. The modern emphasis, however, is on the use of relatively new ideas in Basic, such as abstraction and encapsulation, which aim to make applications easier to develop, understand, and maintain. Any Visual Basic developer unfamiliar with these ideas first has to learn what they are and why they are useful and then has to understand all the quirks of their implementation in Visual Basic 5. The learning curve is not trivial. For example, understanding how the Implements statement produces a virtual class that is Visual Basic 5’s way of implementing polymorphism can require some structural remodeling of one’s thought processes. This is heavy-duty object-oriented programming in the 1990s style. Trying to use it in a production environment without a clear understanding is a prime cause of new and unexpected bugs.
Developers faced with radically new concepts usually go through up to four stages of enlightenment. The first stage has to do with reading and absorbing the theory behind the concept. The second stage includes working with either code examples or actual programs written by other people that implement the new concept. The third stage involves using the new concept in their own code. Only at this point do programmers become fully aware of the subtleties involved and understand how not to write their code. The final stage of enlightenment arrives when the programmer learns how to implement the concept correctly, leaving no holes for the bugs to crawl through.
Some Final Thoughts Developers should take all the time necessary to reach the third and fourth stages of enlightenment when learning new programming concepts or methodologies. Only then should they be allowed to implement these new ideas in production systems.