Book Image

React and React Native - Third Edition

By : Adam Boduch, Roy Derks
Book Image

React and React Native - Third Edition

By: Adam Boduch, Roy Derks

Overview of this book

React and React Native, Facebook’s innovative User Interface (UI) libraries, are designed to help you build robust cross-platform web and mobile applications. This updated third edition is improved and updated to cover the latest version of React. The book particularly focuses on the latest developments in the React ecosystem, such as modern Hook implementations, code splitting using lazy components and Suspense, user interface framework components using Material-UI, and Apollo. In terms of React Native, the book has been updated to version 0.62 and demonstrates how to apply native UI components for your existing mobile apps using NativeBase. You will begin by learning about the essential building blocks of React components. Next, you’ll progress to working with higher-level functionalities in application development, before putting this knowledge to use by developing user interface components for the web and for native platforms. In the concluding chapters, you’ll learn how to bring your application together with a robust data architecture. By the end of this book, you’ll be able to build React applications for the web and React Native applications for multiple mobile platforms.
Table of Contents (33 chapters)
Section 1: React
Section 2: React Native
Section 3: React Architecture

What's new in React?

The third edition of this book includes React features that were introduced after version 16.6.0. In the following sections, I'll give you a brief introduction to the new functionality. Each feature will be covered in greater detail as you make your way through the book.

For now, we will briefly look at the following:

  • Memoizing functional components
  • Cook splitting and loading
  • Hooks

Let's start exploring them.

Memoizing functional components

The React.memo() function is the modern equivalent of the PureComponent class. Memoized components avoid re-rendering if the component data hasn't changed. In the past, you would extend your class component with PureComponent. This would automatically handle checking whether the component data has changed or not and whether or not the component should re-render.

The challenge with this approach is that it is now common for large React applications to have a lot of functional components. Before React.memo(), there was no way to memorize components so that they could avoid re-rendering if no data changes happened. Now, you can pass your functional components to React.memo() and they'll behave like PureComponent.

You can read more about React.memo() here:

Code splitting and loading

Prior to the React.lazy() function, code splitting in large React applications was cumbersome. Code splitting is important for large applications because it reduces the size of the code bundles that are sent to the browser, which can dramatically improve the user experience. Some features of an application might never be used, which means that the code that implements those features is never delivered to the browser. This is a huge efficiency gain.

With the addition of React.lazy(), React acknowledges that code splitting and the user experience of waiting for pieces of the application to load are integral parts of the application, not an afterthought. By combining React.lazy() and the Suspense component, we get fine-grained control over how our app is split up and what happens while the user waits for it to load.

You can read more about code splitting here:


One of the most consequential new features of React is Hooks—functions that extend the behavior of functional React components. Hooks are used to "hook into" the React component machinery from your React components. Instead of relying on classes to build components that have state or that rely on executing side effects when the component is mounted, you can use the React Hooks API to pass functions that handle these cases.

The end result is having more flexibility with how you're able to compose React components since functions are more easily shared between modules than component class methods are. Hooks are the future of how React components are assembled, which will have a big impact on the third edition of this book, where there's a new chapter devoted to Hooks, as well as updated code in all chapters from the second edition.

You can read more about Hooks here: