title: How to create a mutable array of specific class type in Swift
body: <p>I have a class called <code>Bullet</code> and I want to make a mutable array with this class type. Basically the desired outcome I want is, when a user touches the screen a new bullet is spawned. I know in Java you can use an <code>ArrayList</code> to achieve this by adding a new instance to the array list each time. </p>
  
  <p>I'm not sure syntactically how I could achieve in Swift or if it is even possible. 
  This is the code I have for declaring and instance of the <code>Bullet</code> class but how do I make it so that it is a mutable array... </p>
  
  <pre><code>var bullet: Bullet = Bullet()
  </code></pre>
  
  <p>Thank you!</p>