If you are starting with learning React, the best way to get started is to use the in-browser React and Babel libraries. That’s what the Learning React book starts off with as well. Since the printed book may go out-of-sync with the recommended version and path to the libraries, this post will act as an anchor to always reference people to for the latest/recommended starting point.
With that said, here it is:
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>React! React! React!</title> <script src="https://unpkg.com/react@16/umd/react.development.js"></script> <script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script> <script src="https://email@example.com/babel.min.js"></script> </head> <body> <script> </script> </body>
If this matches what the Learning React book says, then great! If it doesn’t, I encourage you to always use the version of the libraries listed here instead of what is printed.