Tell me about React hooks: which ones have you used and for what purposes (useState, useEffect, useRef, useContext, useMemo, useCallback)?

React hooks allow you to use state and other React features in functional components.

• useState — stores the local state of the component.

  const [count, setCount] = useState(0);
  

• useEffect — performs side effects (requests, subscriptions) after rendering.

  useEffect(() => {
    document.title = `You clicked ${count} times`;
  }, [count]);
  

• useRef — stores a mutable object that does not cause re-rendering when changed, often used to access the DOM.

  const inputRef = useRef(null);
  

• useContext — allows using React context to pass data without props.

  const theme = useContext(ThemeContext);
  

• useMemo — memoizes a computed value to avoid unnecessary recalculations.

  const memoizedValue = useMemo(() => computeExpensiveValue(a, b), [a, b]);
  

• useCallback — memoizes a function to prevent recreating it on every render.

  const memoizedCallback = useCallback(() => {
    doSomething(a, b);
  }, [a, b]);
  

I used these hooks for state management, performance optimization, and working with effects and context.