intermediate
Hooks
State, effects, refs, memoization, reducers, and custom hooks under the rules of hooks.
Hooks let function components use state, effects, refs, memoization, reducers, and reusable logic. The rules of hooks — top level only, same order every render — are a frequent interview topic.
Use child topics for useState, useEffect, useMemo, useCallback, useRef, useReducer, and custom hooks.