Functional Thinking

Chapter 2. Shift

Learning a new programming language is easy: you merely learn the new syntax for familiar concepts. For example, if you decide to learn JavaScript, your first stop will be a resource that explains how JavaScript’s if statement works. Typically, developers learn new languages by applying what they know about existing languages. But learning a new paradigm is difficult—you must learn to see different solutions to familiar problems.

Writing functional code doesn’t require a shift to a functional programming language such as Scala or Clojure but rather a shift in the way you approach problems.

A Common Example

Once garbage collection became mainstream, it simultaneously eliminated entire categories of hard-to-debug problems and allowed the runtime to manage a process that is complex and error-prone for developers. Functional programming aims to do the same thing for the algorithms you write, allowing you to work at a higher level of abstraction while freeing the runtime to perform sophisticated optimizations. Developers receive the same benefits of lower complexity and higher performance that garbage collection provides, but at a more intimate level, in the way you devise solutions.

Imperative Processing

Imperative programming describes a style of programming modeled as a sequence of commands (imperatives) that modify state. A traditional for loop is an excellent example of the imperative style of programming: establish an initial state and execute a series of commands for ...