title: Is strong identifier the default with @property statement?
body: <p>I'm learning Objective-C and the Cocoa Framework (via Aaron Hillgass' book) and trying to figure out why the following line includes the "strong" identifier.</p>
  
  <pre><code>@property (strong) NSManagedObjectContext *managedObjectContext;
  </code></pre>
  
  <p>As I understand it, strong is the default so why do I need to explicitly declare it?</p>