title: Instance method 'contains' requires that 'UITextField' conform to 'StringProtocol'
body: <p>I have a tableview that displays a sourceArray with a Name and Category properties.  I want to filter the Category property of the sourceArray based on the users input from a UIAlertController but getting the error &quot;Instance method 'contains' requires that 'UITextField' conform to 'StringProtocol'&quot;. Any help is greatly appreciated.</p>
  <pre><code>var sourceArray = [(Name: String, Category: String, Picture1: UIImage, Picture2: UIImage, Picture3: UIImage, Description: String)]()
  
  @IBAction func filterButton(_ sender: UIBarButtonItem) {
      var textField = UITextField()
      let alert = UIAlertController(title: &quot;Category&quot;, message: nil, preferredStyle: .alert)
      let action = UIAlertAction(title: &quot;Filter&quot;, style: .default) { (action) in
          print(textField)
          let filtered = sourceArray.filter({$0.Category.contains(textField)})
          self.filteredArray = filteredArray.isEmpty ? sourceArray : filtered
          self.tableview.reloadData()
  
      }
      alert.addTextField { (alertTextField) in
          alertTextField.placeholder = &quot;Biceps, Chest, Shoulders, etc.&quot;
          textField = alertTextField
      }
      alert.addAction(action)
      present(alert, animated: true, completion: nil)
      
  }
  </code></pre>