how to change title for a react app code example

Example 1: react set title of page

import React, { useEffect } from 'react'
import ReactDOM from 'react-dom'

const App = () => {
  // This effect runs once, after the first render
  useEffect(() => {
    document.title = "This is a title"
  }, [])
  
  return <h1>Hello, World!</h1>
};

ReactDOM.render(
  <App />,
  document.getElementById('root')
);

Example 2: change title react

import React from 'react'
import ReactDOM from 'react-dom'


class Doc extends React.Component{
  componentDidMount(){
    document.title = "dfsdfsdfsd"
  }

  render(){
    return(
      <b> test </b>
    )
  }
}

ReactDOM.render(
  <Doc />,
  document.getElementById('container')
);