var NumberSelector = React.createClass({

  getInitialState () {

    return { number: 0 };

  },

  handleIncrementClick () {

    this.setState({number: this.state.number + 1})

  },

  handleDecrementClick () {

    this.setState({number: this.state.number - 1}) 

  },

  render () {

    return <div style={{width: 70, textAlign: "center"}}>

      <h2>{this.state.number}</h2>

      <button onClick={this.handleDecrementClick}>-</button>

      <button onClick={this.handleIncrementClick}>+</button>

    </div>;

  }

});

​

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