title: Routing priority confuse about Express
body: <p>All:</p>
  
  <p>I am pretty new to Express.js, say if I specify Routes like:</p>
  
  <pre><code>var routes = require('./routes/index');
  app.use('/', routes);
  app.get('/hello', function(req, res){res.send("hello");});
  </code></pre>
  
  <p>inside index.js, I set routing like:</p>
  
  <pre><code>/* GET home page. */
  router.get('/hello', function(req, res, next) {
    res.render('index', { title: 'Express' });
  });
  
  module.exports = router;
  </code></pre>
  
  <p>This seems both handle same url request, I wonder how does Express decide which handler to use?</p>
  
  <p>Thanks</p>