function App() {
  const [ageFirst, setAgeFirst] = useState(true);
 
  let age, setAge, name, setName;
 
  if (ageFirst) {
    [age, setAge] = useState(20);
    [name, setName] = useState("John");
  } else {
    [name, setName] = useState("John");
    [age, setAge] = useState(20);
  }
 
  return (
    <div>
      <p>age: {age}</p>
      <p>name: {name}</p>
 
      <button onClick={() => setAgeFirst(!ageFirst)}>change</button>
    </div>
  );
}