Book Image

Professional JavaScript

By : Hugo Di Francesco, Siyuan Gao, Vinicius Isola, Philip Kirkbride
Book Image

Professional JavaScript

By: Hugo Di Francesco, Siyuan Gao, Vinicius Isola, Philip Kirkbride

Overview of this book

In depth knowledge of JavaScript makes it easier to learn a variety of other frameworks, including React, Angular, and related tools and libraries. This book is designed to help you cover the core JavaScript concepts you need to build modern applications. You'll start by learning how to represent an HTML document in the Document Object Model (DOM). Then, you'll combine your knowledge of the DOM and Node.js to create a web scraper for practical situations. As you read through further lessons, you'll create a Node.js-based RESTful API using the Express library for Node.js. You'll also understand how modular designs can be used for better reusability and collaboration with multiple developers on a single project. Later lessons will guide you through building unit tests, which ensure that the core functionality of your program is not affected over time. The book will also demonstrate how constructors, async/await, and events can load your applications quickly and efficiently. Finally, you'll gain useful insights into functional programming concepts such as immutability, pure functions, and higher-order functions. By the end of this book, you'll have the skills you need to tackle any real-world JavaScript development problem using a modern JavaScript approach, both for the client and server sides.
Table of Contents (12 chapters)

Async and Await

It has always been the dream of JavaScript developers to handle async functions without the need to write wrappers around them. Then, a new feature was introduced, and that changed everything we know about JavaScript async operations. Consider the code we used in the last exercise:

function getFullRecord(id) {
   return getProfile(id)

It is simple enough because we used promise chaining, but it doesn't really tell us anything more than that, and it appears we are just calling a bunch of functions. What if we could have something like this:

function getFullRecord(id) {
   const profile = getProfile(id);
   const cart = getCart(id);
   const subscription = getSubscription(id);
   return {