title: UITextField Changes Not Being Detected?
body: <p>I have two flag properties that should change when a text field contains an integer, and I have IBActions, when the text field editing ends, that change the flags. When both of the variables are true, those methods should enable a button. I ran the iOS simulator, but the button isn't enabling. I also declared the text field delegate for both the text fields.</p>
  
  <p>I am new to swift, so please be clear with your answer. Also, I haven't set any breakpoints. Here's the code for what I have so far:</p>
  
  <pre><code>var yourWeightFilled = false
  var calorieNumberFilled = false
  
  func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -&gt; Bool {
      // Find out what the text field will be after adding the current edit
      let text = (textField.text as NSString).stringByReplacingCharactersInRange(range, withString: string)
  
      if textField == yourWeightTextField {
          yourWeightFilled = text.toInt() != nil
      } else if textField == calorieNumberTextField {
          calorieNumberFilled = text.toInt() != nil
      }
  
      return true
  }
  
  @IBAction func yourWeightEditingDidEnd(sender: AnyObject) {
      if self.yourWeightFilled &amp;&amp; self.calorieNumberFilled {
          self.calculateButton.enabled = true
      }
      yourWeightTextField.resignFirstResponder()
  }
  
  @IBAction func calorieNumberEditingDidEnd(sender: AnyObject) {
      if self.yourWeightFilled &amp;&amp; self.calorieNumberFilled {
          self.calculateButton.enabled = true
      }
      calorieNumberTextField.resignFirstResponder()
  }
  </code></pre>