How to show/hide component on click in React-redux?

You should add some flag to the state of CommentBox. And if value of this flag is false when don't show ReaplyFrom and vice versa. Heres the code and working example http://codepen.io/anon/pen/KzrzQZ

class ReplyForm extends React.Component {
  constructor() {
    super()
  }
  render(){
    return(
      <div>I'm ReplyForm</div>
    )
  }
}

class CommentBox extends React.Component {
  constructor() {
    super();
    this.state = {
      showReply: false
    }
  }
  onClick(e){
    e.preventDefault();
    this.setState({showReply: !this.state.showReply})
  }
  render() {
    return (
      <div>
        <p>Some comment</p>
         <a onClick={this.onClick.bind(this)} href='#'>Post a reply to this comment</a>
        {this.state.showReply && < ReplyForm / >}
      </div>
    )
  }
}

How about this?

class CommentBox extends Component {
  constructor() {
    super();
    this.state = {
      showForm: false
    }
  }

  render() {
    const showHide = {
      'display': this.state.showStatus ? 'block' : 'none'
    };

    const showReplyForm = () => {
      this.setState({showForm: true});
    };

    return (
      <div>
        <div>
            <p>Some comment</p>
            <a onClick={showReplyForm}>Post a reply to this comment</a>
        </div>
        <div style={showStatus}>
          <ReplyForm />
        </div>
      </div>
    )
  }
}