Just working on a Flickr tutorial project that uses a NSmutableArray and was thinking about one of the methods and how it worked. The array has photos that are loaded from Flickr and the method is removeObject:photo Does it go thru and compare some kind of meta data on the photo? Does it attach something to the photo? What's strange is the the code before that is: Code: NSString *searchTerm = self.searches[indexPath.section]; FlickrPhoto *photo = self.searchResults[searchTerm][indexPath.row]; I'm wondering if they know which photo to grab, why not just delete it based on position. But I'm just curious how they find a photo in an array using a photo as the search key.