When should I use useLayoutEffect in React?

Can you explain when to use useLayoutEffect in React?

Sure! useLayoutEffect is used when you need to perform side effects that require the DOM to be updated before the browser paints. This is useful for measuring the layout or making DOM manipulations that need to happen synchronously.

What’s the difference between useEffect and useLayoutEffect?

The main difference is timing. useEffect runs after the paint, while useLayoutEffect runs synchronously after all DOM mutations but before the browser has a chance to paint.

Can you give me an example of when to use it?

Certainly! If you need to read layout properties (like width or height) and then make adjustments based on that, useLayoutEffect is ideal.

Are there any performance concerns with using useLayoutEffect?

Yes, since it runs synchronously, it can block visual updates, potentially leading to performance issues if overused. It's best to use it only when necessary.