← React Derived State: Why That useState Is Probably a BugQuiz

React Derived State

Test what you just learned about spotting derived state, why syncing it with useEffect costs an extra render, and when useMemo or a key actually applies.

questions7
pass mark70%
resultsat the end

No account needed. Answer all 7 questions, then see your score with every answer explained and a reference to the spec or MDN — pass and you can claim a certificate.