What is Functional Programming?
Functional Programming is, like Object Oriented Programming (OOP), a programming paradigm. There isn't a formal agreed-upon definition of what FP entails, but there are two core concepts most people would agree are central to the paradigm:
- Avoiding mutating state and side-effects
- Using functions as the central building block of programs
Lets discuss each of these in turn.
Source: What is Functional Programming?, an article written by Kjetil Valle.