如何在React类组件中声明和重新分配变量以存储setTimeout引用？

import React, { Component } from 'react';

class MyComponent extends Component {
  constructor(props) {
    super(props);
    this.state = {
      timeoutRef: null
    };
  }

  componentDidMount() {
    // 在组件挂载后，声明并存储setTimeout引用
    const timeoutRef = setTimeout(() => {
      console.log('Timeout completed');
    }, 1000);
    this.setState({ timeoutRef });
  }

  componentWillUnmount() {
    // 在组件卸载前，清除setTimeout引用
    clearTimeout(this.state.timeoutRef);
  }

  render() {
    return <div>My Component</div>;
  }
}

export default MyComponent;