<!DOCTYPE html>
<html>
<head>
 <meta charset="utf-8">
 <title>Plunker</title>
 <script src="https://unpkg.com/react@16.3.2/umd/react.production.min.js"></script>
 <script src="https://unpkg.com/react-dom@16.3.2/umd/react-dom.production.min.js"></script>
 <script src="https://unpkg.com/babel-standalone@6.26.0/babel.min.js"></script>

 <script src="https://unpkg.com/redux@4.0.0/dist/redux.js"></script>
 <script src="https://unpkg.com/react-redux@5.0.7/dist/react-redux.js"></script>
</head>
<body>
 <div id='root'></div>
 <script type="text/jsx" src="script.jsx"></script>
</body>
</html>
const counter = (state = 0, action) => {
  switch (action.type) {
    case 'INCREMENT':
      return state + 1;
    case 'DECREMENT':
      return state - 1;
    default:
      return state;
  }
} 

const Counter = ({
  value,
  onIncrement,
  onDecrement
}) => (
  <div>
    <h1>{value}</h1>
    <button onClick={onIncrement}>+</button>
    <button onClick={onDecrement}>-</button>
  </div>
);

const { createStore } = Redux;
const store = createStore(counter);

const render = () => {
  ReactDOM.render(
    <Counter
      value={store.getState()}
      onIncrement={() =>
        store.dispatch({
          type: 'INCREMENT'           
        })            
      }
      onDecrement={() =>
        store.dispatch({
          type: 'DECREMENT'           
        })            
      }
    />,
    document.getElementById('root')
  );
};

store.subscribe(render);
render();