score:2

Accepted answer
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.14.8/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.14.8/react-dom.js"></script>
<div id="container"></div>

score:1

class App extends React.Component {
  constructor(props) {
    super(props);

    this.state = {
      birthdays: {
        'January': [{
          name: 'Mike',
          date: '1/14/90'
        }, {
          name: 'Joe',
          date: '1/7/92'
        }],

        March: [{
          name: 'Mary',
          date: '3/7/88'
        }]
      }
    }
  }

  render() {
    console.log();
    return (
      <table>   
        <thead>
          <th>
            <td>Month</td>
            <td>Name</td>
            <td>Birthday</td>
          </th>
        </thead>
        <tbody>
        {Object.keys(this.state.birthdays).map((month, key) => {
          return (     
            <tr key={key}>
              {this.state.birthdays[month].map((person, index) => {
                return (
                  <tr key={String(key) + String(index)}>
                    <td>{month}</td>
                    <td>{person.name}</td>
                    <td>{person.date}</td>
                  </tr>
                );
              })} 
            </tr>         
          )
        })}
        </tbody>
      </table>
    );
  }
}

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

score:2

return <table>
  {
    birthdays.map((bday) => (
      <tr>
        <td>{bday.name}</td>
        <td>{bday.date}</td>
      </tr>
    );
  }
</table>

Related Query

More Query from same tag