I never had any interest in developing mobile apps. I used to believe strongly that it was the web, or nothing; that there was no need for yet more applications to install on devices already overflowing with apps. Then, React Native came along. I was already writing React code for web applications and loving it. It turns out that I wasn't the only developer that balked at the idea of maintaining several versions of the same app using different tooling, environments, and programming languages. React Native was created out of a natural desire to take what works well from a web development experience standpoint (React), and apply it to native app development. Native mobile apps offer better user experiences than web browsers. It turns out I was wrong; we do need mobile apps for the time being. But that's okay, because React Native is a fantastic tool. This book is essentially my experience as a React developer for the web and as a less experienced mobile app developer. React Native is meant to be an easy transition for developers who already understand React for the web. With this book, you'll learn the subtleties of doing React development in both mobile and web environments. You'll also learn the conceptual theme of React, a simple rendering abstraction that can target anything. Today, it's web browsers and mobile devices. Tomorrow, it could be anything.

The second edition of this book was written to address the rapidly evolving React project-including state-of-the-art best practices for implementing React components as well as the ecosystem surrounding React. I think it's important for React developers to appreciate how React works and how the implementation of React changes to better support the people who rely on it. I've done my best to capture the essence of React as it is today and the direction in which it's moving, in this edition of React and React Native.