title: Ionic2 constructor, two different classes
body: <p>I'm creating a simple page and I need to NavController and AlertController, as far as I understood constructor should look like this: </p>
  
  <pre><code>  constructor(public alertCtrl: AlertController 
  , navCtrl: NavController) { }
  </code></pre>
  
  <p>my problem is that navController is not recognised later in the code. If I change the line to </p>
  
  <pre><code>constructor(public navCtrl: NavController,
  alertCtrl: AlertController) { }
  </code></pre>
  
  <p>Then <code>alertController</code> stops working. Im pretty sure its some newbie syntax issue. </p>