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Professional JavaScript

You're reading from   Professional JavaScript Fast-track your web development career using the powerful features of advanced JavaScript

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Product type Paperback
Published in Sep 2019
Publisher
ISBN-13 9781838820213
Length 664 pages
Edition 1st Edition
Languages
Tools
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Authors (4):
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Hugo Di Francesco Hugo Di Francesco
Author Profile Icon Hugo Di Francesco
Hugo Di Francesco
Siyuan Gao Siyuan Gao
Author Profile Icon Siyuan Gao
Siyuan Gao
Vinicius Isola Vinicius Isola
Author Profile Icon Vinicius Isola
Vinicius Isola
Philip Kirkbride Philip Kirkbride
Author Profile Icon Philip Kirkbride
Philip Kirkbride
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Toc

Table of Contents (12) Chapters Close

Preface 1. JavaScript, HTML, and the DOM FREE CHAPTER 2. Node.js and npm 3. Node.js APIs and Web Scraping 4. RESTful APIs with Node.js 5. Modular JavaScript 6. Code Quality 7. Advanced JavaScript 8. Asynchronous Programming 9. Event-Driven Programming and Built-In Modules 10. Functional Programming with JavaScript Appendix

Introduction

In the previous chapter, we talked about how event-driven programming is used in Node.js and how we can modify normal callback-based async operations to use async-await and promises. We know that the Node.js core API is built on async-driven architecture. Node.js has one event loop that does the processing for most async and event-based operations.

In JavaScript, the event loops run constantly and digest messages from the callback queue to make sure it is executing the right functions. Without events, we can see that the code is very deeply coupled. For a simple chatroom application, we would need to write something like this:

class Room {
    constructor() {
        this.users = [];
    }
    addUser(user) {
        this.users.push(user);
    }
    sendMessage(message) {
  &...
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