Contents of React Interview Questions

Comprehensive collection of React interview questions and answers covering hooks, components, state management, and best practices.

Common mistakes to avoid when using React Hooks

Here are some mistakes developers often make when working with Hooks:

  • Breaking the Rules of Hooks
    Calling Hooks inside loops, conditions, or nested functions can cause unpredictable behavior.

  • Missing dependencies in useEffect
    Forgetting to add all dependencies can cause bugs. Use linters like ESLint with the React Hooks plugin to catch these issues.

  • Overusing useMemo and useCallback
    Memoization adds complexity and might harm performance if overused for cheap computations.

  • Directly mutating state
    Always return a new copy of objects or arrays when updating state; otherwise, React won't detect changes.

  • Misusing useRef to manage state
    useRef changes won't trigger re-renders. Use useState when UI needs to update.

  • Not cleaning up effects
    Always return a cleanup function inside useEffect when dealing with subscriptions, timers, or event listeners.