import React from 'react';
import ReactDOM from 'react-dom/client';
class Header extends React.Component {
constructor(props) {
super(props);
this.state = {favoritecolor: "red"};
}
componentDidMount() {
setTimeout(() => {
this.setState({favoritecolor: "yellow"})
}, 1000)
}
getSnapshotBeforeUpdate(prevProps, prevState) {
document.getElementById("div1").innerHTML =
"Before the update, the favorite was " + prevState.favoritecolor;
}
componentDidUpdate() {
document.getElementById("div2").innerHTML =
"The updated favorite is " + this.state.favoritecolor;
}
render() {
return (
<div>
<h1>My Favorite Color is {this.state.favoritecolor}</h1>
<div id="div1"></div>
<div id="div2"></div>
</div>
);
}
}
const root = ReactDOM.createRoot(document.getElementById('root'));
root.render(<Header />);