Book Image

Learn ECMAScript - Second Edition

By : MEHUL MOHAN, Narayan Prusty
Book Image

Learn ECMAScript - Second Edition

By: MEHUL MOHAN, Narayan Prusty

Overview of this book

Learn ECMAScript explores implementation of the latest ECMAScript features to add to your developer toolbox, helping you to progress to an advanced level. Learn to add 1 to a variable andsafely access shared memory data within multiple threads to avoid race conditions. You’ll start the book by building on your existing knowledge of JavaScript, covering performing arithmetic operations, using arrow functions and dealing with closures. Next, you will grasp the most commonly used ECMAScript skills such as reflection, proxies, and classes. Furthermore, you’ll learn modularizing the JS code base, implementing JS on the web and how the modern HTML5 + JS APIs provide power to developers on the web. Finally, you will learn the deeper parts of the language, which include making JavaScript multithreaded with dedicated and shared web workers, memory management, shared memory, and atomics. It doesn’t end here; this book is 100% compatible with ES.Next. By the end of this book, you'll have fully mastered all the features of ECMAScript!
Table of Contents (18 chapters)
Title Page
PacktPub.com
Contributors
Preface
Index

Using classes


We saw that JavaScript's object-oriented model is based on constructors and prototype-based inheritance. Well, ES6 classes are just a new syntax for the existing model. Classes do not introduce a new object-oriented model to JavaScript.

ES6 classes aim to provide a much simpler and clearer syntax for dealing with the constructors and inheritance.

In fact, classes are functions. Classes are just a new syntax for creating functions that are used as constructors. Creating functions using classes that aren't used as constructors doesn't make any sense, and offers no benefits.

Rather, it makes your code difficult to read, as it becomes confusing. Therefore, use classes only if you want to use them to construct objects. Let's have a look at classes in detail.

Defining a class

Just as there are two ways of defining functions, function declarations and function expressions, there are two ways to define a class: using the class declaration and the class expression.

The class declaration

To...