var destination = document.querySelector("#container");

ReactDOM.render(
  <div>
    <h3><i>Batman</i></h3>
    <h3><i>Iron Man</i></h3>
    <h3><i>Nicolas Cage</i></h3>
    <h3><i>Mega Man</i></h3>
  </div>,
  destination
);

---------------------------------------------------------

<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <title>Komponenty React</title>
  <script src="https://unpkg.com/react@16/umd/react.development.js"></script>
  <script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
  <script src="https://unpkg.com/babel-standalone@6.15.0/babel.min.js"></script>
</head>

<body>
  <div id="container"></div>
  <script type="text/babel">

  </script>
</body>

</html>

-------------------------------------------------------

class HelloWorld extends React.Component {

}

ReactDOM.render(
  <div>
    <p>Witaj, świecie!</p>
  </div>,
  document.querySelector("#container")
);

---

    return <p>Witaj, komponentowy świecie!</p>
    
---

ReactDOM.render(
  <div>
    <HelloWorld/>
    <HelloWorld/>
    <HelloWorld/>
    <HelloWorld/>
    <HelloWorld/>
    <HelloWorld/>
  </div>,
  document.querySelector("#container")
);

---

class HelloWorld extends React.Component {
  render() {
    return <p>Witaj, {this.props.greetTarget}!</p>
  }
}
---
ReactDOM.render(
  <div>
    <HelloWorld greetTarget="Batman"/>
    <HelloWorld greetTarget="Iron Man"/>
    <HelloWorld greetTarget="Nicolas Cage"/>
    <HelloWorld greetTarget="Mega Man"/>
    <HelloWorld greetTarget="Bono"/>
    <HelloWorld greetTarget="Catwoman"/>
  </div>,
  document.querySelector("#container")
);
---

