JavaScript

INTRODUCTION

THIS BOOK IS FOR ANY JAVASCRIPT (OR TYPESCRIPT) programmer who wants to get up to speed on the latest features added to JavaScript in the last few years, and who wants to know how to stay informed as the language continues to evolve and grow. You can find nearly all of the information in this book somewhere on the web if you look hard enough and you’re cautious about what sites you trust; this book provides all of the technical details in one place, along with showing you how to keep track of the changes as they continue to be made. You can continue to stay up-to-date via the book's website at https://thenewtoys.dev, where I continue covering new features as they're added.

WHAT DOES THIS BOOK COVER?

Here's a glance at what's in each chapter:

• Chapter 1: The New Toys in ES2015–ES2020, and Beyond — begins with introducing various players in the JavaScript world and some important terminology. Then it describes the definition of “The New Toys” for the purposes of the book; covers the way new features are added to JavaScript, how that process is managed, and by whom; and explains how to follow and participate in that process. It finishes by introducing some tools for using the new toys in older environments (or using the very newest toys in current environments).
• Chapter 2: Block-Scoped Declarations: let and const — covers the new declaration keywords let and const and the new scoping concepts they support, including in-depth coverage of scoping in loops, particularly ...