title: isa pointer in objective-c
body: <p>From this reference:</p>
  
  <blockquote>
    <p>When a new object is created, memory for it is allocated, and its
    instance variables are initialized. First among the object’s variables
    is a pointer to its class structure. This pointer, called isa, gives
    the object access to its class and, through the class, to all the
    classes it inherits from.</p>
  </blockquote>
  
  <p>From what I could understand reading <a href="http://developer.apple.com/library/ios/documentation/cocoa/conceptual/ObjCRuntimeGuide/ObjCRuntimeGuide.pdf" rel="noreferrer">this</a> and <a href="http://developer.apple.com/library/ios/documentation/cocoa/conceptual/objectivec/ObjC.pdf" rel="noreferrer">this</a>, it allows, for one, to use introspection but in a pragmatic way (iOS development), <strong>what can a programmer benefit from knowing/understanding this special pointer?</strong></p>