Reactjs Developer

What is Batching in React?

Batching in React means grouping multiple state updates into a single render instead of re-rendering the UI again and again.

When you call setState multiple times, React is smart enough to batch them together and update the UI once, making your app faster and smoother.
Why batching is important?

Improves performance

Reduces unnecessary re-renders

Makes React apps feel fast
Before batching:
Multiple state updates = Multiple renders

With batching:
Multiple state updates = One render

In React 18, batching works even in:
setTimeout
Promises
Event handlers
Async functions

Result: Cleaner code + better performance

Image idea:
State updates → Batch → Single Render

⚠️ React 19 does NOT delete useEffect everywhere

Yes, React 19 simplifies DOM logic…

But when it comes to data fetching, useEffect is still doing the heavy lifting 💪

📌 This pattern is still 100% valid & recommended:
✔ Fetch data on mount
✔ Handle async logic safely
✔ Cancel requests on unmount using AbortController
✔ Prevent memory leaks & race conditions

💡 Why useEffect still matters here?

Because network requests are side-effects, not DOM concerns.

🧠 New mental model:
• DOM effects → Callback refs (React 19 magic ✨)
• Data effects → useEffect (still the right tool)
🔥 Clean code isn’t about deleting hooks
🔥 It’s about using the right hook for the right job

Save this if you’re confused about

👉 “Should I remove useEffect in React 19?”

Short answer: No. Use it wisely.