What are the best practices for using useMemo and useCallback in React?

What are the best practices for using useMemo and useCallback in React?

The best practices for using useMemo and useCallback include using them to optimize performance, especially in large components. You should use useMemo to memoize expensive calculations and useCallback to memoize functions that are passed as props to child components.

When should I avoid using useMemo?

You should avoid using useMemo when the computation is inexpensive or when the dependencies change frequently, as the overhead of memoization may outweigh the performance benefits.

Can you give an example of useCallback?

Sure! Here's a simple example:

const handleClick = useCallback(() => {
  console.log('Button clicked!');
}, []);

return <button onClick={handleClick}>Click me</button>;

This memoizes the handleClick function so it doesn't get recreated on every render.

How do useMemo and useCallback affect rendering?

Both useMemo and useCallback help prevent unnecessary re-renders by ensuring that functions and values are only recalculated when their dependencies change, thus improving performance.