FUNCTIONAL Programming: WHAT MAKES IT SO COOL

Functional programming. What is it and why is it better?

I became aware of functional programming via F#. No, I am not a F# developer, although I would love to become more proficient. (Goal list 2023: added.) It did, however, pique my curiosity.

At first, I imagined it was something used for math or science programming. As a LOB programmer, I didn’t see much use for it. But I was beginning to learn more about asynchronous programming, and The Unicorn Project made me aware of how it could make this easier.

So… what is it? Basically, it is a way of thinking about programming that isolates side effects. What are side effects? Well, suppose you have a program that calculates student grades. For this program to work, you will need to have a source for the data. Probably a file or a database or something else. Then you need to take that data and perform the calculation. Then you need to output that data so the user can see the results.

In functional programming, you want to have as many pure functions as possible. With the student grades, the actual calculation would be performed in a pure function. The parts that interact with a file or database or whatever, are the side effects. Once you have a pure function, you can pass that function into another method that will use it to do the calculations. That’s right! In addition to passing your methods data, you can also pass functions, which are pieces of codes capable of taking raw data and transforming into the format that you need.

Being able to isolate these functions makes things easier in so many ways. It improves testability, reusability, makes your program more modular, and other benefits.

It does, admittedly, take some time to get used to thinking of functions as true first-class citizens, but once you have, it will be hard to go back to anything else! Trust me, this will revolutionize your programming life.