如何在React组件中保留初始状态？

class MyComponent extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      initialData: 'Initial Data'
    };
  }
  
  // ...
}

class MyComponent extends React.Component {
  state = {
    initialData: 'Initial Data'
  };
  
  componentDidMount() {
    // 在组件挂载后设置初始状态
    this.setState({ initialData: 'Initial Data' });
  }
  
  // ...
}

import React, { useState } from 'react';

function MyComponent() {
  const [initialData, setInitialData] = useState('Initial Data');
  
  // ...
}