In functional programming (FP), pure functions are the basic building blocks. In object-oriented programming (OOP), “objects” are the basic building blocks. Objects encapsulate data and functions. Pure functions and objects can both be reused and combined to build complex logic. My point is that FP and OOP may be regarded as opposite sides of the same coin:
I don’t want to discourage functional programming, but make sure you don’t oversell it: read Is Functional Programming overtaking the IT Industry?