title: Subclassing memory allocations question
body: <p>I have a basic question about subclassing a class with objects:</p>
  
  <p>@interface Myclass : NSObject{</p>
  
  <p>UIImage *image;
  NSString *string;
  ParticleSystem *system;
  Object *obj;
  Object2 *obj2;
  }</p>
  
  <p>If I subclass this MyClass class, and I initialise only a few of these objects defined in the superclasses header, what happens to all the other unallocated definitions in terms of memory?
  The reason I ask, I have a class with many, many definitions and i've been subclassing it for simplicity sake, but my subclass only needs a fraction of these definitions.</p>
  
  <p>Is it worth just subclassing NSObject and redefining the needed variables rather than subclassing MyObject?</p>
  
  <p>Thanks, 
  Oliver.</p>