title: Incorrect integration into React props
body: <p>I am trying to implement my first React-Redux app and got <code>TypeError: Cannot read property 'map' of undefined</code> from <code>bundle.js</code>. I guess it is associated with <code>jokes</code> array and its incorrect integration into my React jokeList component props:</p>
  
  <pre><code>import React from 'react';
  import {connect} from 'react-redux';
  
  class ListOfJokes extends React.Component {
    constructor(props) {
      super(props)
    }
  
    render() {
      const {jokes} = this.props;
      return (
        &lt;ul&gt;
          {jokes.map(joke =&gt; (&lt;li&gt;joke&lt;/li&gt;))}
        &lt;/ul&gt;
      )
    } 
  }
  
  const mapStateToProps = state =&gt; ({
    jokes: state.jokes
  })
  
  export default connect(mapStateToProps, null)(ListOfJokes);
  </code></pre>
  
  <p>What is actually wrong with it?</p>