Book Image

Learn ECMAScript - Second Edition

By : MEHUL MOHAN, Narayan Prusty
Book Image

Learn ECMAScript - Second Edition

By: MEHUL MOHAN, Narayan Prusty

Overview of this book

Learn ECMAScript explores implementation of the latest ECMAScript features to add to your developer toolbox, helping you to progress to an advanced level. Learn to add 1 to a variable andsafely access shared memory data within multiple threads to avoid race conditions. You’ll start the book by building on your existing knowledge of JavaScript, covering performing arithmetic operations, using arrow functions and dealing with closures. Next, you will grasp the most commonly used ECMAScript skills such as reflection, proxies, and classes. Furthermore, you’ll learn modularizing the JS code base, implementing JS on the web and how the modern HTML5 + JS APIs provide power to developers on the web. Finally, you will learn the deeper parts of the language, which include making JavaScript multithreaded with dedicated and shared web workers, memory management, shared memory, and atomics. It doesn’t end here; this book is 100% compatible with ES.Next. By the end of this book, you'll have fully mastered all the features of ECMAScript!
Table of Contents (18 chapters)
Title Page

Chapter 1. Getting Started with ECMAScript

ECMAScript 2017 (ES8) was released at the end of June 2017 by Technical Committee number 39 (TC39). It's part of ECMA, the institution that standardizes the JavaScript language under the ECMAScript specification. Currently, the standard aims to publish a new ES specification version once a year. ES6 was published in 2015 and ES7 was published in 2016. A lot changed when ES6 was released (arrow functions, classes, generators, module loaders, async programming, and so on) and even more interesting stuff keeps happening, as time goes by.

In this chapter, we'll be starting off with the fundamentals of JavaScript, starting off with ES6 basics and heading towards ES8 stuff. Furthermore, we'll be taking a look at some interesting aspects of traditional JS such as closures, and some new ones such as arrow functions.

As an autodidact, I highly recommend not only reading this book, but also trying to apply whatever you're learning here in some small but interesting projects. This will help you to retain a lot of stuff effortlessly.

In this chapter, we'll be covering:

  • Creating block-scoped variables using the let keyword
  • Creating constant variables using the const keyword
  • The spread operator and the rest parameter
  • Hoisting
  • Extracting data from iterables and objects using a destructuring assignment
  • Arrow functions
  • Closures and how to deal with them
  • Use of semicolons in JavaScript
  • Benchmarking let versus var versus const
  • The new syntaxes for creating object properties