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

JavaScript modules 101

The practice of breaking down programs and libraries into modules is called modular programming.

In JavaScript, a module is a collection of related objects, functions, and other components of a program or library that are wrapped together and isolated from the scope of the rest of the program or library.

A module exports some variables to the outside program to let it access the components wrapped by the module. To use a module, a program needs to import the module and the variables exported by the module.

A module can also be split into further modules called sub-modules, thus creating a module hierarchy.

Modular programming has many benefits. Some benefits are as follows:

  • It keeps our code both cleanly separated and organized by splitting it into multiple modules
  • Modular programming leads to fewer global variables, that is, it eliminates the problem of global variables, because modules don't interface via the global scope, and each module has its own scope
  • It makes code...