What is useEffect cleanup in React?

What is useEffect cleanup in React?

In React, useEffect cleanup is a function that runs when a component unmounts or before the effect runs again. It helps to prevent memory leaks.

Can you give me an example of how to implement it?

Sure! Here's a simple example:

useEffect(() => {
  const timer = setTimeout(() => {
    console.log('Timer triggered!');
  }, 1000);

  return () => clearTimeout(timer); // Cleanup function
}, []);

What happens if I forget to include the cleanup function?

If you forget the cleanup function, it can lead to memory leaks, especially if the effect creates subscriptions or timers that continue running after the component unmounts.

Are there any best practices for using useEffect?

Yes! Always include cleanup functions for subscriptions or timers, and be mindful of dependencies to avoid unnecessary re-renders.