Book Image

Object-Oriented JavaScript - Third Edition

By : Ved Antani, Stoyan STEFANOV
5 (1)
Book Image

Object-Oriented JavaScript - Third Edition

5 (1)
By: Ved Antani, Stoyan STEFANOV

Overview of this book

JavaScript is an object-oriented programming language that is used for website development. Web pages developed today currently follow a paradigm that has three clearly distinguishable parts: content (HTML), presentation (CSS), and behavior (JavaScript). JavaScript is one important pillar in this paradigm, and is responsible for the running of the web pages. This book will take your JavaScript skills to a new level of sophistication and get you prepared for your journey through professional web development. Updated for ES6, this book covers everything you will need to unleash the power of object-oriented programming in JavaScript while building professional web applications. The book begins with the basics of object-oriented programming in JavaScript and then gradually progresses to cover functions, objects, and prototypes, and how these concepts can be used to make your programs cleaner, more maintainable, faster, and compatible with other programs/libraries. By the end of the book, you will have learned how to incorporate object-oriented programming in your web development workflow to build professional JavaScript applications.
Table of Contents (25 chapters)
Object-Oriented JavaScript - Third Edition
About the Authors
About the Reviewer
Customer Feedback
Built-in Functions
Regular Expressions

Chapter 9. Promises and Proxies

This chapter introduces the important concept of asynchronous programming and how JavaScript is an ideal language to utilize it. The other topic that we will cover in this chapter is meta programming with proxies. These two concepts are introduced in ES6.

In this chapter, our primary focus is to understand asynchronous programming, before we jump into the language - specific constructs, let's spend time in understanding the concept first.

The first model-the synchronous model-is where it all began. This is the simplest model of programming. Each task is executed one at a time, and only after the first task completes execution can, the next task start. When you program in this model, we expect that all tasks before the current task are complete and there is no error. Take a look at the following figure:

The single threaded asynchronous model is a familiar model we all know. However, this model can be wasteful and optimized. For any nontrivial programs composed...