title: Cannot read property 'length' of undefined sending array from node to jade
body: <p>Hi I'm rendering jade from node by this</p>
  
  <pre><code>router.get("/register", function (req, res) {
      var countries = [1, 2, 3];
      res.render("./account/register", {
          countries: countries
      });
  });
  </code></pre>
  
  <p>and here is my jade template</p>
  
  <pre><code>extends ../layout
  block content   
      each val,t in countries
          p= val
  </code></pre>
  
  <p>and it gets error  Cannot read property 'length' of undefined
  i'm using express 4x, I'm trying to solve this problem almost 2 days</p>