React钩子介绍了如何在初始useEffect之后跳过特定的useEffect

useEffect(() => {
  // 副作用代码
  return () => {
    // 清理函数，组件卸载时执行
  };
}, [依赖项数组]);

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

function MyComponent() {
  const [data, setData] = useState(null);
  const [hasFetched, setHasFetched] = useState(false);

  useEffect(() => {
    if (!hasFetched) {
      fetchData();
      setHasFetched(true);
    }
  }, [hasFetched]);

  const fetchData = async () => {
    const response = await fetch('https://api.example.com/data');
    const result = await response.json();
    setData(result);
  };

  return (
    <div>
      {data ? <div>{data}</div> : <div>Loading...</div>}
    </div>
  );
}

export default MyComponent;

useEffect(() => {
  // 副作用代码
}, [依赖项]);

useEffect(() => {
  // 副作用代码
  return () => {
    // 清理函数
  };
}, [依赖项]);