title: confusion about actions in Redux
body: <p>I'm not able to figure out whether Redux actions are synchronous or asynchronous. Consider this:</p>
  
  <pre><code>addBook () =&gt; {
    console.log( "current books:  ",this.props.books );
  
    const book = {
        id: 3,
        title: "Percy Jackson"
    };
  
    this.props.addBook(book); // firing off a new action [ is it synchronous or asynchronous ]
  
    console.log( "updated books:  ",this.props.books ); // shouldn't these be new props
  }
  </code></pre>
  
  <p>From above, both <code>current books</code> and <code>updated books</code> are same, though UI is updated and I'm guessing new props from the store are also passed to this component via <code>mapStateToProps</code> method.</p>
  
  <p>What am I missing?</p>