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

Shimming methods with Babel Polyfill


In the previous two recipes, we saw how to create a client bundle and load it into a browser. This make it possible to use ES modules in source code without breaking compatibility with older browsers.

However, there are also new methods available in newer versions of the language that we'll be using in later chapters.

This recipe demonstrates how to use the babel-polyfill library to support those methods.

Getting ready

This recipe assumes that you have the code created in earlier recipes in this chapter, and that you have installed Python and know how to start the static HTTP server. Please visit the earlier recipes or copy the code.

How to do it...

  1. Open your command line application and navigate to the directory containing the 02-creating-client-bundles package.
  2. Start the Python HTTP server.
  3. Update the main.js file to use the Array.prototype.values method, and use for..of to loop over the resulting iterator:
import { atlas, saturnV } from './rockets/index.js...