title: express route return necessary or not
body: <p>i use express framework for my webapp. I pickup some codes from book, looked at this code, this a route to a page.</p>
  
  <pre><code>app.post('/register', function(req, res) {
    var firstName = req.param('firstName', '');
    var lastName = req.param('lastName', '');
    var email = req.param('email', null);
    var password = req.param('password', null);
  
    if ( null == email || email.length &lt; 1
         || null == password || password.length &lt; 1 ) {
      res.send(400);
      return;
    }
  </code></pre>
  
  <p>what has the return for meaning here, is necessary?  </p>