What are useCallback and useMemo in React?

Can you explain what useCallback and useMemo do in React?

Sure! useCallback is a hook that returns a memoized version of a callback function, which helps prevent unnecessary re-renders.

When should I use useCallback?

You should use useCallback when passing callbacks to optimized child components that rely on reference equality to prevent re-renders.

And what about useMemo?

useMemo is used to memoize expensive calculations so that they are only recalculated when their dependencies change.

Can you give me an example of both in a component?

Absolutely! Here's a simple example: you can use useCallback for a button click handler and useMemo for a calculated value based on props.