Search icon CANCEL
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
Mastering JavaScript Functional Programming

You're reading from   Mastering JavaScript Functional Programming In-depth guide for writing robust and maintainable JavaScript code in ES8 and beyond

Arrow left icon
Product type Paperback
Published in Nov 2017
Publisher Packt
ISBN-13 9781787287440
Length 386 pages
Edition 1st Edition
Languages
Arrow right icon
Author (1):
Arrow left icon
Federico Kereki Federico Kereki
Author Profile Icon Federico Kereki
Federico Kereki
Arrow right icon
View More author details
Toc

Table of Contents (15) Chapters Close

Preface 1. Becoming Functional - Several Questions 2. Thinking Functionally - A First Example FREE CHAPTER 3. Starting Out with Functions - A Core Concept 4. Behaving Properly - Pure Functions 5. Programming Declaratively - A Better Style 6. Producing Functions - Higher-Order Functions 7. Transforming Functions - Currying and Partial Application 8. Connecting Functions - Pipelining and Composition 9. Designing Functions - Recursion 10. Ensuring Purity - Immutability 11. Implementing Design Patterns - The Functional Way 12. Building Better Containers - Functional Data Types 13. Bibliography
14. Answers to Questions

Questions


7.1. Sum as you will. The following exercise will help you understand some of the concepts we dealt with above, even if you solve it without using any of the functions we saw in the chapter. Write a sumMany() function that lets you sum an indeterminate quantity of numbers, in the following fashion. Note that when the function is called with no arguments, the sum is returned:

     let result = sumMany((9)(2)(3)(1)(4)(3)());
     // 22

7.2. Working stylishly. Write an applyStyle() function that will let you apply basic styling to strings, in the following way. Use either currying or partial application:

     const makeBold = applyStyle("b");
     document.getElementById("myCity").innerHTML =    
     makeBold("Montevideo");
     // <b>Montevideo</b>, to produce
Montevideo

     const makeUnderline = applyStyle("u");
     document.getElementById("myCountry").innerHTML =    
     makeUnderline("Uruguay");
     // <u>Uruguay</u>, to produce
Uruguay

7.3. Currying...

lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at £16.99/month. Cancel anytime