The name of the method is followed by the equal sign, open and close parentheses, the fat arrow symbol, and then the message body. When you click the button element, the updateContent method is provided with a value for this, which will update the div content.
Create React App
Type the following command to create a new react app:
npx create-react-app demo
Now, go to the project folder:
cd demo
Now, update default App.js with below code snippet
src\App.js
import React, { Component } from 'react'; class App extends Component { constructor(props) { super(props); this.state = { message: "Default Content" } } updateContent = () => { this.setState({ message: "Updated Content!"}); } render() { return ( <div> <div className="h1 bg-secondary text-white text-center p-2"> { this.state.message } </div> <div className="text-center"> <button className="btn btn-secondary" onClick={this.updateContent}> Click Me </button> </div> </div> ); } } export default App;