Functional Programming in JavaScript: How and Why

Functional Programming is a programming paradigm where you mostly construct and structure your code using functions.  

Features:

• First-class citizens functions: you can always insert functions inside a function without any restrictions present.
• A higher-order function: a function that gets a function as an argument.
• Function Composition: an act of composing/creating functions that allow you to further simplify and compress your functions by taking functions as an argument and return an output.

  Benefits:

• It doesn’t have side-effects and it’s immutable
• It’s clean, straightforward and KISS