December COP Quiz

What is React?

• A framework

• A library

• A database

• A server

Which of the following is true about React 19's Document Metadata API?

• Allows inline metadata updates for React Server Components.

• Helps in managing SEO data on the server and client efficiently.

• Prevents errors during server-side rendering.

• Optimizes hydration performance for metadata tags.

What does the virtual DOM do?

• Updates the real DOM directly

• Enhances performance by batching updates

• Is an abstraction of the real DOM

• Both 2 and 3

Which React hook is used to handle side effects?

• useState

• useRef

• useEffect

• useReducer

What is React 19's new `useOptimistic` hook used for?

• Handling form validation

• Handling errors

• Managing optimistic UI states

• Improving performance

Which feature in React 19 improves hydration error reporting?

• useErrorBoundary

• Hydration Error Diffs

• Improved useDebugValue

• useRef cleanup functions

What is React 19's `useFormStatus` used for?

• Managing loading states in forms

• Handling form validation errors

• Both 1 and 2

• Handling server requests

What does the React 19 compiler improve?

• Error handling

• Rendering performance

• Server-side rendering

• All of the above

Which of the following is true about React 19's useFormStatus hook?

• It manages validation states only.

• It combines loading and validation state management for forms.

• It improves component hydration.

• It optimizes form performance.

What does React’s useActionState hook help with?

• Performing side effects.

• Managing state transitions for async actions.

• Memoizing values.

• Optimizing renders.