What are React re-renders and how can I optimize them?

What are React re-renders and how can I optimize them?

React re-renders occur when the state or props of a component change, causing it to update. To optimize, you can use techniques like memoization, React.memo, and useCallback.

Can you explain how React.memo works?

Sure! React.memo is a higher-order component that prevents a functional component from re-rendering if its props haven't changed. This can improve performance in certain scenarios.

What about useCallback? How does it help with re-renders?

useCallback returns a memoized version of the callback function that only changes if one of the dependencies has changed. This helps prevent unnecessary re-renders of child components that rely on that callback.

Are there any tools to analyze re-renders in my React app?

Yes! You can use React DevTools to analyze component re-renders. It provides insights into which components are re-rendering and why.