function Counter() {
  const [count, setCount] = useState(0);
  const [countObj, setCountObj] = useState({ count: 0 });
 
  console.log("re-rendered");
 
  return (
    <div>
      <button onClick={() => setCount(0)}>update count</button>
      <button onClick={() => setCountObj({ count: 0 })}>update countObj</button>
    </div>
  );
}