What is the useEffect hook in React?

What is the useEffect hook in React?

The useEffect hook lets you perform side effects in function components. It runs after every render by default.

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

Sure! You can use it to fetch data when a component mounts. Here's a simple example:

useEffect(() => {
  fetchData();
}, []);

What does the empty array mean in that example?

The empty array means that the effect runs only once, similar to componentDidMount in class components.

What happens if I include variables in the array?

If you include variables, the effect will run whenever those variables change, allowing you to respond to state updates.