How do you mimic componentDidMount and componentWillUnmount with hooks?

Short answer: ✅ componentDidMount: useEffect(() => { console.log("Component mounted"); }, []); // Empty array = run once on mount ✅ componentWillUnmount: useEffect(() => { const id = setInterval(() => console.log("tick"), 1000);

Example code

return () => { clearInterval(id); // Cleanup console.log("Component unmounted"); }; }, []);

Real-world example (ShopNest)

ShopNest’s cart icon uses useState for count and useEffect to load the cart once on mount.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.