Do I need to import react in every file?

Question

I've found out that components without import React from 'react'; lines works well.

I've added import React from 'react'; to the first line of .jsx files conventionally. And I saw many open source with this line.

Then why do we add this line unnecessarily?

Answer 1

You no longer need to import React from "react". Starting from the release 17 of React, JSX is automatically transformed without using React.createElement.
However, other exports like hooks must be imported.