Functional Programming — and OOP

What’s real difference compared to OOP — what about hybrid approaches ?

Myself have been using OOP for more than 20 years now. OOP and procedural programming have dominated the software world form decades now. Nowadays, Functional Programming (FP) has been a new trending, moving us to a new era. Is FP a new paradigm? Hell no! FP has been out there since 1930, starting with Lambda calculus, then LISP appeared in the 1950s.

FP is sometimes seen in opposition to OOP. That is misleading. These approaches complementary and most systems tend to use both. I recommend reading this article, Functional Core & Imperative Shell (FC&IS) for more details about how we can use both approaches.

The Functional Programming

If we use OOP, we are likely talking about using a procedural programming language, such Java, C++, C, there are certainly bugs that are hard to fix, or recreate. It may take a long series of steps to make them show up, for many reasons. One reason is that we need to be able to track all changes that occurs while running the workflow or scenario inside the program, because there are likely hundreds of attributes used at different places (classes and methods) at runtime. Briefly, classes are intended to encapsulate states and are composed of several…