title: What is __NSArrayI and __NSArrayM? How to convert to NSArray?
body: <p>What is __NSArrayI and __NSArrayM? </p>
  
  <p>__NSArrayI(or M) cause "unrecognized selector" error.</p>
  
  <p>How to convert to NSArray?</p>
  
  <hr>
  
  <p>I did test to parse json, twitter api.</p>
  
  <p><a href="http://api.twitter.com/1/followers/ids.json?cursor=-1&amp;screen_name=twitterapi">http://api.twitter.com/1/followers/ids.json?cursor=-1&amp;screen_name=twitterapi</a></p>
  
  <p>==> works fine. parsed object is NSCFDictionary class. 
  (This dictionary contains __NSArrayM class)</p>
  
  <p><a href="http://api.twitter.com/1/statuses/user_timeline.json?&amp;screen_name=twitterapi">http://api.twitter.com/1/statuses/user_timeline.json?&amp;screen_name=twitterapi</a></p>
  
  <p>==> error. parsed object is __NSArrayM class.</p>