Q27: What is the difference between useEffect and useLayoutEffect?
useEffect runs asynchronously after browser paint. useLayoutEffect runs synchronously after all DOM mutations but before the browser paints screen updates, ideal for measuring DOM dimensions.
Key Takeaways
useEffectis non-blocking and executes after browser layout and paint.useLayoutEffectfires synchronously before paint, preventing visual layout flickering.
Knowledge Check
When should you prefer useLayoutEffect over useEffect?