react hook example

function Button(props) {
  function handleClick() { 
    props.incrementCount(props.incrementBy);
  }
	return <button onClick={handleClick}>+{props.incrementBy}</button>
}

function Display(props) {
  return <div>{props.count}</div>
}

function App() {
  const [count, setCount] = useState(0);
  function handleIncrement(incrementBy) { 
    setCount(count + incrementBy);
  }
  return(
    <div>
        <Button incrementCount = {handleIncrement} incrementBy = {1}/>
        <Button incrementCount = {handleIncrement} incrementBy = {2}/>
        <Button incrementCount = {handleIncrement} incrementBy = {5}/>
        <Button incrementCount = {handleIncrement}  incrementBy = {10}/>
        <Display count = {count}/>
    </div>
  );
}

ReactDOM.render(
  <App />, 
  document.getElementById('mountNode'),
);