如何在react中获取状态的初始数据

class MyComponent extends React.Component {
  constructor(props) {
    super(props);
    this.state = { data: [] };
  }
  // ...
}

class MyComponent extends React.Component {
  componentDidMount() {
    // 发起异步请求获取数据
    fetchData().then(data => {
      this.setState({ data: data });
    });
  }
  // ...
}

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

function MyComponent() {
  const [data, setData] = useState([]);

  useEffect(() => {
    // 发起异步请求获取数据
    fetchData().then(data => {
      setData(data);
    });
  }, []);

  // ...
}