A React useCallback Hook Primer

React hooks, introduced in version 16.8, enhance the development of functional components by providing utilities such as state, context, ref, effect, and performance hooks, including useCallback, useMemo, and memo. The useCallback hook specifically helps optimize React applications by memoizing callback functions, thus preventing unnecessary re-renders. It achieves this by caching the callback function and recreating it only when dependencies change, which is crucial for performance when passing functions as props to child components. Memoization, the underlying technique, stores computed results to avoid redundant calculations, similar to caching operations in memory. While React.memo is used to prevent re-renders by memoizing components, it falls short when props include functions due to referential equality issues. In such cases, useCallback becomes essential, as it resolves these issues by ensuring functions are not recreated unnecessarily. The article demonstrates the practical application of useCallback in a React project, comparing it with useMemo, which caches computed values rather than functions. It emphasizes the importance of using useCallback judiciously to enhance performance without complicating code.