title: RemoveObjectAtIndex for NSMuatableArray of NSmutableArrays in iOS is crashing
body: <p>I am using <code>NSMutableArray</code> and trying to the remove the object from the <code>NSMutableArray</code> then it is crashing at</p>
  <p><strong>[[self.sectionsArray objectAtIndex:indexPath.section] removeObjectAtIndex:indexPath.row];</strong></p>
  <p><code>.h</code> is like</p>
  <pre><code>NSMutableArray *sectionsArray;
  @property (nonatomic, retain) NSMutableArray *sectionsArray;
  
  
  
  .m is like:
  
   @synthesize sectionsArray;
  
   #pragma mark - TableView Delegate
  
   - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
   {
  // Perform segue to candy detail
    
  NSLog(@&quot;section: %d row: %d&quot;, indexPath.section, indexPath.row);
  NSLog(@&quot;section :%@&quot;, [[self.sectionsArray objectAtIndex:indexPath.section] objectAtIndex:indexPath.row]);
  [[self.sectionsArray objectAtIndex:indexPath.section] removeObjectAtIndex:indexPath.row];
  //    [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationLeft];
    
   }
  </code></pre>
  <p>crash log is like :</p>
  <pre><code> 2014-01-28 11:56:24.989 CandySearch[828:c07] section: 2 row: 0
   2014-01-28 11:56:24.991 CandySearch[828:c07] section :&lt;Candy: 0x75a5a70&gt;
   2014-01-28 11:56:24.992 CandySearch[828:c07] -[__NSArrayI removeObjectAtIndex:]: unrecognized selector sent to instance 0x75d8c90
   2014-01-28 11:56:24.992 CandySearch[828:c07] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSArrayI removeObjectAtIndex:]: unrecognized selector sent to instance 0x75d8c90'
   *** First throw call stack:
   (0x1c9b012 0x10d8e7e 0x1d264bd 0x1c8abbc 0x1c8a94e 0x370d 0xcc285 0xcc4ed 0xad65b3 0x1c5a376 0x1c59e06 0x1c41a82 0x1c40f44 0x1c40e1b 0x1bf57e3 0x1bf5668 0x1cffc 0x1d52 0x1cc5 0x1)
   libc++abi.dylib: terminate called throwing an exception
  </code></pre>
  <p>I can see the object at that index.but still it is crashing
  why?</p>