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


A collection is an object that stores multiple elements as a single unit. ES6 introduced various new collection objects to provide better ways of storing and organizing data.

The array was the only collection object available in ES5. Now we have ArrayBuffers, SharedArrayBuffers, Typed Arrays, Sets, and Maps, which are built in collection objects.

Let's explore the different collection objects provided in JavaScript.


Elements of arrays can be of any type, such as strings, numbers, objects, and so on. Arrays can grow dynamically. The problem with arrays is that they are slow in terms of execution time and occupy more memory. This causes issues while developing applications that require too much computation and deal with plenty of numbers. Therefore array buffers were introduced to tackle this issue.

An array buffer is a collection of 8-bit blocks in memory. Every block is an array buffer element. The size of an array buffer needs to be decided while creating it; therefore...