React Counter

index.html

<div id="root">
    <!-- This element's contents will be replaced with your component. -->
</div>

react-counter.markdown

React Counter

A Pen by Dorothea on CodePen.

License.

script.babel

class Counter extends React.Component {
  constructor(props) {
    super(props);
    this.state = { count: 0 };
    this.increment = this.increment.bind(this);
    this.decrement = this.decrement.bind(this);
  }
  
  render() {
    return (
      <div>
        <h3> Counter </h3>
        <div onClick={this.increment}> + </div>
        <div> {this.state.count} </div>
        <div onClick={this.decrement}> - </div>
      </div>
    )
  }
  
  decrement() {
    this.setState({count: --this.state.count});
  }
  
   increment() {
    this.setState({count: ++this.state.count});
  }
}

ReactDOM.render(
  <Counter />,
  document.getElementById('root')
);

scripts

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.3.1/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.3.1/react-dom.min.js"></script>