Introduction
Functional programming leans heavily on the mathematical definition of functions. Mathematical functions are defined through a declaration expression. The functional programming style is also declarative (as opposed to imperative programming) and promotes expressions over statements.
JavaScript has functional programming constructs built into it. Unlocking the functional programming style in JavaScript is crucial to reaching a deeper understanding of the language and its ecosystem.
As part of each section, React, Redux, and DOM access and testing patterns in JavaScript will be used to illustrate pragmatic functional programming in JavaScript. More recent developments such as GraphQL and backend for frontends (BFFs) will also be included to show how functional programming permeates both the present and the future of the JavaScript programming language.
Functional programming concepts can explain why Redux reducers and React render functions can't contain API...