Unfortunately, some time has passed again since the last post. In the last post I wrote something about the history of functional and imperative programming. This one is now to deal with the, compared to imperative programming, different way of thinking. The source code examples shown here are based on Java for the imperative examples and Haskell for the functional examples. I will try to use only functions available in the language standard and not library functions.

Functional programming is on everyone’s lips and concepts from functional programming are being adopted everywhere in imperative languages. At the moment I am also taking a closer look at these concepts and would like to publish my findings here in the form of a series of articles. But let’s start with a short historical review.