React Добавить кнопку при выборе переключателя

Использование документов React doc1doc2doc3

Попробуй это:

class Radio extends React.Component {
  constructor(props) {
    super(props);
    this.state = {radio: 0};
    this.onRadioChanged = this.onRadioChanged.bind(this);
  }

  onRadioChanged(event) {
      this.setState({radio: parseInt(event.target.value, 10)});
  }

  render() {
    return (
      <div>
      <input type = "radio"
        value = {0} 
        checked = {this.state.radio === 0} 
        onChange = {this.onRadioChanged} />
      Option 1
      <input type = "radio"
        value = {1} 
        checked = {this.state.radio === 1} 
        onChange = {this.onRadioChanged} />
      Option 2
      {this.state.radio === 1? <button>Hi!</button> : null}
      </div>
    );
  }
}

React.render(
    <Radio/>, 
    document.body
);