What are cleanup functions in useEffect?

What are cleanup functions in useEffect?

Cleanup functions in useEffect are used to clean up side effects when a component unmounts or before the effect runs again.

Can you give me an example of a cleanup function?

Sure! If you set up a subscription in useEffect, the cleanup function can unsubscribe when the component unmounts.

How do I implement a cleanup function in my React component?

You can return a function from the useEffect hook. This function will be called when the component unmounts or before the effect runs again.

Are there any common mistakes to avoid with cleanup functions?

Yes, a common mistake is forgetting to include dependencies in the dependency array, which can lead to memory leaks.