React's Legacy #

React has changed a lot since 2013. The iterations of its library, how React applications are written, and especially its components have all changed drastically. However, many React applications were built over the last few years, so not everything was created with the current status quo in mind. This section of the book covers React's legacy. However, I won't cover all that's considered legacy in React, because some features have been revamped more than once.

Throughout this section, we will compare a modern React application to its legacy version. We'll discover that most differences between modern and legacy React are due to class components versus function components.