Book Image

Mastering JavaScript Functional Programming

By : Federico Kereki
Book Image

Mastering JavaScript Functional Programming

By: Federico Kereki

Overview of this book

Functional programming is a programming paradigm for developing software using functions. Learning to use functional programming is a good way to write more concise code, with greater concurrency and performance. The JavaScript language is particularly suited to functional programming. This book provides comprehensive coverage of the major topics in functional programming with JavaScript to produce shorter, clearer, and testable programs. You’ll delve into functional programming; including writing and testing pure functions, reducing side-effects, and other features to make your applications functional in nature. Specifically, we’ll explore techniques to simplify coding, apply recursion for loopless coding, learn ways to achieve immutability, implement design patterns, and work with data types. By the end of this book, you’ll have developed the JavaScript skills you need to program functional applications with confidence.
Table of Contents (22 chapters)
Title Page
About the Author
About the Reviewer
Customer Feedback
Connecting Functions - Pipelining and Composition
Answers to Questions


8.1. Headline capitalization. Let's define headline-style capitalization to require that a sentence is all written in lowercase, except the first letter of each word. (The real definition of this style is more complicated, so let's simplify it for this question.) Write a function headline(sentence) that will receive a string as an argument and return an appropriately capitalized version. Spaces separate words. Build this function by composing smaller functions:

     console.log(headline("Alice's ADVENTURES in WoNdErLaNd")); 
     // Alice's Adventures In Wonderland

8.2. Pending tasks. A web service returns a result such as follows, showing, person by person, all their assigned tasks. Tasks may be finished (done===true) or pending (done===false). Your goal is to produce an array with the IDs of the pending tasks for a given person, identified by name, which should match the responsible field. Solve this by using composition or pipelining:

     const allTasks = {
         date: "2017...