Disclaimer: The author is a coworker of mine at Monitise Group.

First things first: it's a good book. It's covers a lot of area, and it has a *lot* of usable sample code; there's an excellent chance that you can see things and immediately apply them to your own projects. It also covers the stuff which is a pain to find good information about online, such as the C frameworks (EventKit, AddressBook, etc). I know from experience that Apple's sample code for this tends to be unhelpful, and I spotted at least two flat out wrong things in Apple's AddressBook documentation last year, so having a good book for the C frameworks is nice. It also covers much of the iOS 4.0 stuff, such as multitasking. (Older books tend to either not cover it because iOS 4.0 only came out in June 2010, or they rushed it because they desperately needed to have something on the page about it. This book gives it a decent treatment.)

What's not so good is that the book tries to walk a tightrope between being a beginner book and an advanced book, and ends up in the middle somewhere. There's a lot of overview material, such as refreshers on the basics of retain/release memory management, that advanced iOS programmers will already know, but which have large gaps that less experienced programmers will fall into without even realizing it. For example (and only people who know some Objective-C will understand what I mean here), that overview of retain/release memory management gives a *paragraph* to autorelease, which mostly suggests using manual release instead. I can understand that argument and its advantages, even if I don't agree with it. However, the great majority of objects you deal with in an Objective-C app - including almost every NSString you make - were already autoreleased beginners book, why do the overviews not teach you *everything* you need to know?

Bear in mind that this is a good book, even though I spent more time talking about the negatives than the positives; it's just that it cannot be your only Objective-C book. You *need* some experience in writing apps for iOS or the Mac before you can use it. I wish they'd taken out the basics, but them in some other book, and crammed in some more advanced-level material...but then, these days, if a book covered every 'advanced' thing in iOS in enough detail to make me happy, I'd have to take it off the shelf with a forklift.

some very handy examples there i wish there were some more applied examples such as how and when I should mix two or more gesture recognizers. i have some problem with that but i think i will find my answer eventually either in this book or somewhere else. the networking chapter was nice. The material I struggled with from this chapter was the whole caching stuff the author talked about. i think the example about caching files on disk is a bit difficult to understand... actually not a bit but really difficult to understand!!! but I will have to read it again to fully get it. This is one of the few places in the book where I still am struggling to learn the example code. the rest of the example codes in this chapter are pretty easy to learn. it might be that this particular example will be difficult no matter how you implement it because the author goes into explaining how you can download a file from a URL store it on the disk keep its time stamp and if you make another request to download the file check the timestamp and return the file from cache if for example the expiry of that file has not come to pass. pretty difficult concept hence the difficulty of that example. What I would like to see in the next edition of this book would be some other new subjects such as AirPrint.

Disclosure: I'm an O'Reilly Author and developer of the Great iPhone Development Video series. That being said, I'm not one for pulling punches when I see issues with with people's code (ask anyone I've ever code reviewed :).

This is the book I wish I'd had when I started developing for the iPhone. I started writing apps about two weeks after the infamous Apple Developer NDA was lifted and information started trickling out onto the Internet. If I'd have had a book like the iOS Cookbook I could have saved myself many hours of painful trial and error while learning Objective C and what is now the iOS API.

This is not really a book for a beginning iOS programmer. It's a book for someone who's done a couple of simple apps and has the basic idiom down. If you're looking to learn Objective-C or the mechanics of writing an iPhone app, this book will not help you. But if you can already write a functional app, the code snippets in this book will trim lots of time off of your learning curve when it comes to implementing more sophisticated features like Core Data, gestures, etc.

There are a few areas where the examples could be clearer, and it's clearly impossible to cover some of the more sophisticated functions of areas like Core Data in 620 pages. But overall this is an excellent REFERENCE for new and experienced app developers alike, and I'd recommend adding it to your library.