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

Understanding object-oriented JavaScript

Before we proceed with ES6 classes, let's refresh our knowledge of JavaScript data types, constructors, and inheritance. While learning classes, we will be comparing the syntax of  constructors and prototype-based inheritance with the syntax of classes. Therefore, it is important to have a good grasp of these topics.

The JavaScript data types

JavaScript variables hold (or store) data (or values). The type of data variables that they hold is called the data type. In JavaScript, there are seven different data types: number, string, Boolean, null, undefined, symbol, and object.

When it comes to holding objects, variables hold the object reference (that is, the memory address) instead of the object itself. If you're coming from a C/C++ background, you can relate them to pointers, but not exactly.

All data types other than objects are called primitive data types.


The arrays and functions are actually the JavaScript objects. A lot of things are objects under...