title: Adding Elements to Optional Array turning up nil?
body: <p>So here's what I got:</p>
  
  <ul>
  <li>Owner Class</li>
  <li>Pet Class</li>
  <li>PetType Class</li>
  </ul>
  
  <p><strong>Owner Class</strong></p>
  
  <p><em>This class simply declares a variable <strong>pet</strong> of type <strong>Pet?</em></strong></p>
  
  <pre><code>class Owner {
    var pet: Pet?
  }
  </code></pre>
  
  <p><strong>Pet Class</strong></p>
  
  <p><em>This class simply declares an empty array of <strong>PetType</em></strong></p>
  
  <pre><code>class Pet {
    var pets = [PetType]()
  }
  </code></pre>
  
  <p><strong>PetType Class</strong></p>
  
  <p><em>Two stored variables: <strong>petType</strong>(e.g. Dog), and <strong>petName</strong>(e.g. Harris) and a basic <strong>init</strong> method that takes two parameters: <strong>petType</strong> and <strong>petName</em></strong></p>
  
  <pre><code>class PetType {
    var petType: String
    var petName: String
  
    init(petType: String, petName: String) {
      self.petType = petType
      self.petName = petName
    }
  }
  </code></pre>
  
  <p><strong>Note:</strong> This was all done in a <em>Playground</em></p>
  
  <pre><code>let owner = Owner() // returns {nil}
  var firstPet = PetType(petType: "Dog", petName: "Harris") // returns {petType "Dog" petName "Harris"}
  owner.pet?.pets.append(firstPet) // returns nil
  owner.pet?.pets[0].petName // returns nil
  </code></pre>
  
  <p>What am I doing wrong here?</p>