How do you handle side effects with useEffect? useEffect से side effects कैसे handle करते हैं?

// Basic useEffect
function Component() {
  useEffect(() => {
    console.log('Component mounted or updated');
  });
}

// Run only on mount
function Component() {
  useEffect(() => {
    fetch('/api/data')
      .then(res => res.json())
      .then(data => setData(data));
  }, []); // Empty dependency array
}

// Run when dependency changes
function Component({ id }) {
  useEffect(() => {
    fetch(`/api/user/${id}`)
      .then(res => res.json())
      .then(data => setUser(data));
  }, [id]); // Run when id changes
}

// Cleanup function
function Component() {
  useEffect(() => {
    const timer = setInterval(() => {
      console.log('Timer');
    }, 1000);
    
    // Cleanup
    return () => clearInterval(timer);
  }, []);
}