title: Swift if statement - multiple conditions separated by commas?
body: <p>Looking at a Swift <a href="https://developer.apple.com/library/prerelease/ios/referencelibrary/GettingStarted/DevelopiOSAppsSwift/Lesson8.html#//apple_ref/doc/uid/TP40015214-CH16-SW1" rel="noreferrer">example</a>:</p>
  
  <pre><code>if let sourceViewController = sender.sourceViewController as? MealViewController, meal = sourceViewController.meal {
      ...
  }
  </code></pre>
  
  <p>The doc states:</p>
  
  <blockquote>
    <p>... the code assigns that view controller to the local
    constant sourceViewController, and checks to see if the meal property
    on sourceViewController is nil.</p>
  </blockquote>
  
  <p>Question: Does Swift let you have multiple conditions in your if statement when separated by commas (as in this example with the comma after <code>MealViewController</code>)?   </p>
  
  <p>Haven't seen this in the docs.</p>