如何从UseEffect挂钩返回值

import React, { useEffect, useState } from 'react';

const MyComponent = () => {
  const [data, setData] = useState(null);
  
  useEffect(() => {
    let isMounted = true;
    const fetchData = async () => {
      const response = await fetch('https://api.example.com/data');
      const result = await response.json();
      if (isMounted) {
        setData(result);
      }
    };
    
    fetchData();
    
    return () => {
      isMounted = false;
    };
  }, []);
  
  return (
    <div>
      {data ? (
        <ul>
          {data.map(item => (
            <li key={item.id}>{item.name}</li>
          ))}
        </ul>
      ) : (
        <p>Loading...</p>
      )}
    </div>
  );
};

export default MyComponent;