state.js

import React, { useState } from "react";
import { render } from "react-dom";

const Button = () =>{
  const [counter, setCounter] = useState(0);
  return (
    <div>
      <p>Presionado: { counter }</p>
      <button onClick= {()=> setCounter(counter + 1)}>Click me!</button>
    </div>
  )
}

const App = () => {
  return <div><Button /></div>;
}

render(<App />, document.getElementById("react-app"));