ReactJS - .JS vs .JSX

Question

There is something I find very confusing when working in React.js.

There are plenty of examples available on internet which use .js files with React but many others use .jsx files.

I have read about JSX files and my understanding is that they just let you write HTML tags within your JavaScript. But the same thing can be written in JS files as well.

So what is the actual difference between .js and .jsx ?

Answer 1

There is none when it comes to file extensions. Your bundler/transpiler/whatever takes care of resolving what type of file contents there is.

There are however some other considerations when deciding what to put into a .js or a .jsx file type. Since JSX isn't standard JavaScript one could argue that anything that is not "plain" JavaScript should go into its own extensions ie., .jsx for JSX and .ts for TypeScript for example.

There's a good discussion here available for read

Answer 2

In most of the cases it’s only a need for the transpiler/bundler, which might not be configured to work with JSX files, but with JS! So you are forced to use JS files instead of JSX.

And since react is just a library for javascript, it makes no difference for you to choose between JSX or JS. They’re completely interchangeable!

In some cases users/developers might also choose JSX over JS, because of code highlighting, but the most of the newer editors are also viewing the react syntax correctly in JS files.