What is React useEffect?

Can you explain what the useEffect hook in React is?

Sure! The useEffect hook is used to perform side effects in functional components. It runs after the render and can be used for tasks like data fetching, subscriptions, or manually changing the DOM.

How does useEffect differ from componentDidMount?

Great question! useEffect can mimic componentDidMount, componentDidUpdate, and componentWillUnmount, depending on how you use its dependency array.

Can you give me an example of how to use useEffect?

Absolutely! Here's a simple example:

useEffect(() => {
  // Your code here, e.g., fetching data
}, []); // Empty array means it runs once after the initial render.

What happens if I don't provide a dependency array?

If you don't provide a dependency array, useEffect will run after every render, which can lead to performance issues.