Book Image

React Key Concepts

By : Maximilian Schwarzmüller
Book Image

React Key Concepts

By: Maximilian Schwarzmüller

Overview of this book

As the most popular JavaScript library for building modern, interactive user interfaces, React is an in-demand framework that’ll bring real value to your career or next project. But like any technology, learning React can be tricky, and finding the right teacher can make things a whole lot easier. Maximilian Schwarzmüller is a bestselling instructor who has helped over two million students worldwide learn how to code, and his latest React video course (React — The Complete Guide) has over six hundred thousand students on Udemy. Max has written this quick-start reference to help you get to grips with the world of React programming. Simple explanations, relevant examples, and a clear, concise approach make this fast-paced guide the ideal resource for busy developers. This book distills the core concepts of React and draws together its key features with neat summaries, thus perfectly complementing other in-depth teaching resources. So, whether you've just finished Max’s React video course and are looking for a handy reference tool, or you've been using a variety of other learning materials and now need a single study guide to bring everything together, this is the ideal companion to support you through your next React projects. Plus, it's fully up to date for React 18, so you can be sure you’re ready to go with the latest version.
Table of Contents (16 chapters)

What Is React?

React is a JavaScript library, and if you take a look at the official webpage (Official React website and documentation:, you learn that it's actually a "JavaScript library for building user interfaces".

But what does this mean?

It should be clear what JavaScript is and why you use JavaScript in the browser (React is mostly a browser-side JavaScript library). JavaScript allows you to add interactivity to your website since, with JavaScript, you can react to user events and manipulate the page after it was loaded. This is extremely valuable as it allows you to build highly interactive web user interfaces.

But what is a "library" and how does React help with "building user interfaces"?

While you can have philosophical discussions about what a library is (and how it differs from a framework), the pragmatic definition of a library is that it's a collection of functionalities that you can use in your code to achieve results that would normally require more code and work from your side. Libraries help you write better and shorter code and enable you to implement certain features more quickly. In addition, since you can focus on your "core business logic", you not only move faster but are also likely to produce better code since you don't have to reinvent the wheel for problems that have been solved before by others.

React is such a library—one that focuses on providing functionalities that help you create interactive and reactive user interfaces. Indeed, React deals with more than web interfaces (i.e. websites loaded in browsers). You can also build native mobile devices with React and React Native, which is another library that utilizes React under the hood. No matter which platform you're targeting though, creating interactive user interfaces with just JavaScript can quickly become very complex and overwhelming.


The focus of this book is on React in general, and for simplicity, the focus lies on React for websites. With projects like React Native, you can also use React to build user interfaces for native mobile apps. The React concepts covered in this book still apply, no matter which target platform is chosen. But examples will focus on React for web browsers.