title: Difficulty trying to get number of rows for a UITableView with multiple sections
body: <p>My app is crashing and it's caused by my number of rows in section method. It looks ok to me though. </p>
  
  <p>I'm looping using the amount of sections I have and with each iteration I'm getting the number of rows for that specific section and setting the value of a var returned at the end of the method to the Int that represents the number of rows. How ever the app crashes. </p>
  
  <p><strong>Title for header in sections:</strong> </p>
  
  <pre><code> override func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -&gt; String? {
          return _sections[section]
      }
  </code></pre>
  
  <p><strong>Number of sections in table view:</strong></p>
  
  <pre><code>override func numberOfSectionsInTableView(tableView: UITableView) -&gt; Int {
  
      for location in objects {
  
          var resortName = location["resort"] as NSString
  
          if !contains(_sections, resortName) {
              _sections.append(resortName)
          }
  
      }
  
      return _sections.count
  }
  </code></pre>
  
  <p><strong>Number of rows in section method:</strong></p>
  
  <pre><code>override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -&gt; Int {
  
      var rowsInSection = 0 as Int
  
      for var i = 0; i &lt; tableView.numberOfSections(); i++ {
  
          rowsInSection += tableView.numberOfRowsInSection(i)
      }
  
      return rowsInSection
  }
  </code></pre>
  
  <p>objects is an NSArray of PFObjects.</p>