Functional programming is a programming paradigm that minimizes side effects using mathematical functions.
- mathematical function: also called pure function, which always returns the same results only if the same input values are given.
- side-effect: changes in global states. Side effects can incur unexpected outcomes in your code. It is therefore very important to manage all ‘actions’ that are in your code. To minimize these risks, the functional programming paradigm commands you to get rid of as many side effects as you can.
In functional programming, codes can be one of these three categories.
- Action: A code that returns different values depending on when or how many times it has been executed.
- Calculation: A code that returns the same result, given the same input.
- Data: A code that is always the same value even without execution.
Calculations over actions and data over calculations. This dogma aligns with distributed systems, which are increasingly becoming popular these days. Converting action codes into calculation codes would also make it easier to manipulate the code base.
You should learn about first-class abstractions while practicing sorting codes in the three categories above.
First-class abstraction is to handle functions like values.
- Passing the function as a parameter to another function
- Returning a function within a function
- Assign the function to a variable
- Involve the function in a data structure
In the following posts, we’ll talk about some prerequisites ahead of our functional journey. Luckily, the stories about how functional programming can be used in the real world are just around the corner! They would help you to take advantage of functional programming on your working code base.
Stay tuned!