how to add functions in react code example

Example 1: react functional components

const component = () => {
console.log("This is a functional Component");
}

Example 2: react native function

class Foo extends Component {
  handleClick() {
    console.log('Click happened');
  }
  render() {
    return <button onClick={this.handleClick.bind(this)}>Click Me</button>;
  }
}