title: Passing a value from one object into another with Objective-C
body: <p>I have a class called GameScene, with is a subclass of a cocos2d Scene. </p>
  
  <p>In there I have two layers. GameLayer and ControlsLayer. You can probably tell already that I want the ControlsLayer to move stuff around in the GameLayer. To be precise, I'm trying to control a cPBody in the GameLayer from the ControlsLayer. </p>
  
  <p>At the moment, I'm trying to route the instructions from the ControlsLayer, back up into the GameScene and then back down into the GameLayer. If that makes sense. Anyway, I can't get it to work. I have a PHP background so I think I'm incorrectly applying my PHP experience to Obj-C. </p>
  
  <p>My thinking is, I should be able to access a property inside a class/object using something like</p>
  
  <pre><code>aThing *someThing = someInstance-&gt;aThing;
  </code></pre>
  
  <p>From the sample code I've been looking at, it looks like this should work. But it doesn't.  Here's the code, stripped down to as much as possible <a href="http://pastebin.com/d49c9d0be" rel="nofollow noreferrer">http://pastebin.com/d49c9d0be</a></p>
  
  <p>Rather than knowing how to fix this particular issue, The question is, what don't I understand?</p>