Exemplo de useState - Curso React.

useState.jsx

import logo from './logo.svg';
import './App.css';
import { useState } from 'react';

function App() {
  const [reverse, setReverse] = useState(false);
  const [counter, setCounter] = useState(0);
  const reverseClass = reverse ? 'reverse' : '';

  const handleClick = () => {
    setReverse(!reverse);
  };

  const handleIncrement = () => {
    setCounter(counter + 1);
  };

  return (
    <div className="App">
      <header className="App-header">
        <img src={logo} className={`App-logo ${reverseClass}`} alt="logo" />

        <h1>Contador: {counter}</h1>

        <p>
          <button type="button" onClick={handleClick}>
            Reverse {reverseClass}
          </button>
        </p>
        <p>
          <button type="button" onClick={handleIncrement}>
            Increment {counter}
          </button>
        </p>
      </header>
    </div>
  );
}

export default App;

useState.jsx.css

.App {
  text-align: center;
}

.App-logo {
  height: 40vmin;
  pointer-events: none;
}

@media (prefers-reduced-motion: no-preference) {
  .App-logo {
    animation: App-logo-spin infinite 20s linear;
  }

  .reverse {
    animation: App-logo-spin-reverse infinite 20s linear;
  }
}

.App-header {
  background-color: #282c34;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-size: calc(10px + 2vmin);
  color: white;
}

.App-link {
  color: #61dafb;
}

@keyframes App-logo-spin {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

@keyframes App-logo-spin-reverse {
  from {
    transform: rotate(360deg);
  }
  to {
    transform: rotate(0deg);
  }
}