React -尝试将获取的数据保存到变量中，但变量返回空

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

function DataFetchingComponent() {
  const [data, setData] = useState(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState(null);

  useEffect(() => {
    const fetchData = async () => {
      try {
        const response = await fetch('https://api.example.com/data');
        const result = await response.json();
        setData(result);
      } catch (err) {
        setError(err);
      } finally {
        setLoading(false);
      }
    };

    fetchData();
  }, []); // 空依赖数组确保只在组件挂载时执行一次

  if (loading) return <div>Loading...</div>;
  if (error) return <div>Error: {error.message}</div>;

  return (
    <div>
      {/* 使用data渲染组件 */}
      {data && data.map(item => (
        <div key={item.id}>{item.name}</div>
      ))}
    </div>
  );
}

export default DataFetchingComponent;