FAQ: book and supplementary material

2 FAQ: book and supplementary material

This chapter answers questions you may have and gives tips for reading this book.

2.1 How to read this book

2.1.1 In which order should I read the content in this book?

This book is three books in one:

You can use it to get started with JavaScript as quickly as possible:
- Start reading with “Using JavaScript: the big picture” (§8).
- Skip all chapters and sections marked as “advanced”, and all quick references.
It gives you a comprehensive look at current JavaScript. In this “mode”, you read everything and don’t skip advanced content and quick references.
It serves as a reference. If there is a topic that you are interested in, you can find information on it via the table of contents or via the index. Due to basic and advanced content being mixed, everything you need is usually in a single location.

Exercises play an important part in helping you practice and retain what you have learned.

2.1.2 Why are some chapters and sections marked with “(advanced)”?

Several chapters and sections are marked with “(advanced)”. The idea is that you can initially skip them. That is, you can get a quick working knowledge of JavaScript by only reading the basic (non-advanced) content.

As your knowledge evolves, you can later come back to some or all of the advanced content.

2.2 I own a digital version

2.2.1 How do I submit feedback and corrections?

The HTML version of this book (online, or ad-free archive in the paid version) has a link at the end of each chapter that enables you to give feedback.

2.2.2 How do I get updates for the downloads I bought at Payhip?

The receipt email for the purchase includes a link. You’ll always be able to download the latest version of the files at that location.
If you opted into emails while buying, you’ll get an email whenever there is new content. To opt in later, you must contact Payhip (see bottom of payhip.com).

2.2.3 How do I upgrade from a smaller package to a larger one or an older package to a newer one?

The book’s homepage explains how to do that.

2.3 I own the print version (“JavaScript for impatient programmers”)

2.3.1 Can I get a discount for a digital version?

If you bought the print version, you can get a discount for a digital version. The homepage explains how.

Alas, the reverse is not possible: you cannot get a discount for the print version if you bought a digital version.

2.3.2 How do I submit feedback and corrections?

Before reporting an error, please go to the online version of “Exploring JavaScript” and check the latest release of this book. The error may already have been corrected online.
If the error is still there, you can use the comment link at the end of each chapter to report it.
You can also use the comments to give feedback.

2.4 Notations and conventions

2.4.1 What is a type signature? Why am I sometimes seeing static types in this book?

For example, you may see:

Number.isFinite(num: number): boolean

That is called the type signature of Number.isFinite(). This notation, especially the static types number of num and boolean of the result, are not real JavaScript. The notation is borrowed from the compile-to-JavaScript language TypeScript (which is mostly just JavaScript plus static typing).

Why is this notation being used? It helps give you a quick idea of how a function works. The notation is explained in detail in “Tackling TypeScript”, but is usually relatively intuitive.