Book Image

ECMAScript Cookbook

By : Ross Harrison
Book Image

ECMAScript Cookbook

By: Ross Harrison

Overview of this book

ECMAScript Cookbook follows a modular approach with independent recipes covering different feature sets and specifications of ECMAScript to help you become an efficient programmer. This book starts off with organizing your JavaScript applications as well as delivering those applications to modem and legacy systems. You will get acquainted with features of ECMAScript 8 such as async, SharedArrayBuffers, and Atomic operations that enhance asynchronous and parallel operations. In addition to this, this book will introduce you to SharedArrayBuffers, which allow web workers to share data directly, and Atomic operations, which help coordinate behavior across the threads. You will also work with OOP and Collections, followed by new functions and methods on the built-in Object and Array types that make common operations more manageable and less error-prone. You will then see how to easily build more sophisticated and expressive program structures with classes and inheritance. In the end, we will cover Sets, Maps, and Symbols, which are the new types introduced in ECMAScript 6 to add new behaviors and allow you to create simple and powerful modules. By the end of the book, you will be able to produce more efficient, expressive, and simpler programs using the new features of ECMAScript. ?
Table of Contents (20 chapters)
Title Page
Copyright and Credits
Dedication
PacktPub.com
Contributors
Preface
Index

Installing and configuring - Firefox


Subsequent recipes will assume an environment that is capable of using ES modules. There are two strategies for accomplishing this: creating a build step that collects all the modules used into a single file for the browser to download, or using a browser that is capable of using ES modules. This recipe demonstrates the latter option.

Getting ready

To step through this recipe, you need a computer with an operating system (OS) that is supported by Firefox. It supports recent versions of Windows and macOS, as well as a large number of Linux distributions. Most likely, if your OS doesn't support Firefox, you are already aware of this.

How to do it...

  1. To install Firefox, open a browser and enter the following URL:https://www.mozilla.org/firefox.
  2. Click the button that says Download to download the installer.
  3. After the installer has finished downloading, double click the installer and follow the onscreen instructions.
  4. To configure Firefox, open the Firefox browser and enter the following URL: about:config.
  5. The menu will allow you to enable advanced and experimental features. If you see a warning, click the button that says I accept the risk!
  6. Find the dom.moduleScripts.enabled setting, and double-click it to set the value to true, as shown in following screenshot:

How it works...

Firefox supports ES modules, but disables them by default. This allows developers to experiment with the feature, while the majority of users are not exposed to it.

There's more...

The same as the Installing and configuring - Chrome section.