title: Instance member cannot be used on type of custom class
body: <p>I have a classe named "whisky builder" which only initiates the new Whisky. Now i would like to add the new added whiskies in my "WhiskyOverViewController". But I face the following problem:</p>
  
  <pre><code>class WhiskyOverViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
  
  @IBOutlet weak var tableView: UITableView!
  
  var whiskyArray = [WhiskyBuilder]()
  let stringArray = whiskyArray.map({$0.whiskyName!})
  var whiskies = [Character: [String]]()
  var objectsArray = [Object]()
  </code></pre>
  
  <p>In the line of "stringArray" I get the error "Instance member 'whiskyArray' cannot be used on type 'WhiskyOverViewController'. Why am I not able to use the whiskyArray-variable there?</p>
  
  <p>Thanks in advance for your help</p>