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)

OOP in JavaScript

Because of the popularity of JavaScript in web development, it is used mainly in a functional way. This led many developers to the assumption that there is no way to do OOP in JavaScript. Even before the release of the ES6 standard, there was a way to define a class: by using functions. You might have seen this way of defining a class before in legacy frontend code. For example, if you want to create a class called Food, you would have to write something like this:

function Food(name) { = name;
var leek = new Food("leek");
console.log(; // Outputs "leek"

After the release of ES6, an increasing number of developers adopted the modern way of writing JavaScript classes using the class keyword. In this chapter, we will be going over ways to declare classes using the ES6 standard.

Defining a Class in JavaScript

Before we dive into the latest syntax to define a class in JavaScript, let's go over...