where to bind this in react code example

Example 1: react onclick parameter

import React from 'react';

const ExampleComponent = () => {
  
  function sayHello(name) {
    alert(`hello, ${name}`);
  }
  
  return (
    <button onClick={() => sayHello('James')}>Greet</button>
  );
}

export default ExampleComponent;

Example 2: react bind function to component

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