Book Image

Mastering JavaScript Object-Oriented Programming

Book Image

Mastering JavaScript Object-Oriented Programming

Overview of this book

ECMAScript 6 introduces several new Object-Oriented features that drastically change the way developers structure their projects. Web developers now have some advanced OOP functionality at their disposal to build large-scale applications in JavaScript. With this book, we'll provide you with a comprehensive overview of OOP principles in JavaScript and how they can be implemented to build sophisticated web applications. Kicking off with a subtle refresher on objects, we'll show you how easy it is to define objects with the new ES6 classes. From there, we'll fly you through some essential OOP principles, forming a base for you to get hands-on with encapsulation. You'll get to work with the different methods of inheritance and we'll show you how to avoid using inheritance with Duck Typing. From there, we'll move on to some advanced patterns for object creation and you'll get a strong idea of how to use interesting patterns to present data to users and to bind data. We'll use the famous promises to work with asynchronous processes and will give you some tips on how to organize your code effectively. You'll find out how to create robust code using SOLID principles and finally, we'll show you how to clearly define the goals of your application architecture to get better, smarter, and more effective coding. This book is your one-way ticket to becoming a JavaScript Jedi who can be counted on to deliver flexible and maintainable code.
Table of Contents (18 chapters)
Mastering JavaScript Object-Oriented Programming
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface

Managing dynamic typing


Data types are one of the basic features that ensure consistency throughout an application. Some operations can be made only on specific data types and checking if a value is of a valid data type is crucial to avoid runtime exceptions. Most compiled Object-Oriented Programming languages have a static type system that asks the developer to declare the allowed type of a variable and check the code before it runs. JavaScript is a dynamic language—it does not require you to declare a specific data type for a variable. Since the content of a variable can change during the execution, data type checking of its value is performed just when the value itself is used. Let's recall some basic notions with some examples.

Dynamic data types

We know that a variable does not have an associated type declaration in JavaScript. It can contain any value and its type depends on its content. This does not mean that JavaScript does not support data types. It just means that a variable is...