Many years ago, I took part in the development of a taxi-hailing mobile app that is still widely used today. I don’t know what kind of code they’re running now, but in those early days, the driver assignment code –if I remember it correctly– was similar in spirit to the grossly simplified example that follows. There are five levels of nested if statements in less than 30 lines of code. It doesn’t look so bad, some might say, but it’s not difficult to imagine how complicated this code can become with just a few more checks…
I can’t find it right now, but there is some explanation in “Clean Code” why switches shouldn’t be used all over the place.
Google for “replace conditional with polymorphism”.
Just checked and it is in “Clean Code” - Chaper 17; Section G23 “Prefer Polymorphism to if/else or switch/case”.
This is really terrible advice. Sometimes it’s better to do that, but definitely not in the example from this article.
If anyone says you should always prefer polymorphism to switches they are a bloody idiot.
Thank you!