What is the difference between useEffect and useLayoutEffect in React?

What is the difference between useEffect and useLayoutEffect in React?

useEffect runs after the DOM has been painted, while useLayoutEffect runs synchronously after all DOM mutations.

When should I use useLayoutEffect instead of useEffect?

You should use useLayoutEffect when you need to read layout from the DOM and synchronously re-render before the browser paints.

Can you give an example of when to use each?

Sure! Use useEffect for data fetching, and useLayoutEffect for animations or measurements that need to happen before painting.

Are there any performance implications of using one over the other?

Yes, useLayoutEffect can block visual updates, so it may lead to performance issues if overused. Use it only when necessary.