What is the useEffect dependency array in React?

Can you explain what the useEffect dependency array is in React?

Sure! The useEffect dependency array is a second argument you pass to the useEffect hook. It tells React when to run the effect.

What happens if I leave the dependency array empty?

If you leave it empty, the effect will run only once after the initial render, similar to componentDidMount.

What if I include variables in the dependency array?

Including variables means the effect will re-run whenever those variables change, allowing you to respond to state updates.

Can you give an example of how to use it?

Of course! For example, useEffect(() => { console.log('Count changed:', count); }, [count]); will log the count whenever it changes.