title: What does isa mean in objective-c?
body: <p>I would like to know the meaning of the below written lines with an example. I'm unable to understand what the lines actually mean. The lines are from google's objective-c coding guidelines.</p>
  <blockquote>
  <p><strong>Initialization</strong><br />
  Don't initialize variables to 0 or nil in the init method; it's redundant.</p>
  <p>All memory for a newly allocated object is initialized to 0 (except for isa), so don't clutter up the init method by re-initializing variables to 0 or nil.</p>
  </blockquote>