/*
you have to define an event handler before you can pass one anywhere. 

How do you define an event handler in React?

You define an event handler as a method on the component class, just like the render method.
*/

class Example extends React.Component {
  handleEvent() {
    alert(`I am an event handler.
      If you see this message,
      then I have been called.`);
  }

  render() {
    return (
      <h1 onClick={this.handleEvent}>
        Hello world
      </h1>
    );
  }
}