Call Javascript function from ReactJS

class HelloJavascript extends Component {
  constructor(props) {
    super(props);
    this.myJavascriptClick = this.myJavascriptClick.bind(this);
  }

  myJavascriptClick() {
    console.log('Click happened');
  }

  render() {
    return <button onClick={this.myJavascriptClick}>Click Me</button>;
  }
}



Note: 

Above function can also be used like..

myJavascriptClick = () => {
    console.log('Click happened');
  }

Inline function can be used like below..

<button onClick={() => alert('hello world'))}>
      Click me!

</button>