It is very good & convenience pocket reference book for Objective-C programming particular for new Objective-C programmer.

The big complaint I have is that I am new to Objective C and the author decided to change the terminology for Instance Variables or iVars to fields. So while reading this book I have to stop at every word "field" and substitute iVar or Instance Variable in my mind but it is such a common word that it gets lost when reading. This is very frustrating and no other book I've read on Obj-C uses the term "field" like this, so this seems mostly the authors personal choice.

Otherwise it is a good reference.

I have just about every book on Objective-C that you can find. Mainly because I love books. The two that I find most helpfull as a non-programmer who is self-teaching are this little gem and 'Programming in Objective-C'. What I like about this book is that it shows the basic form and structure used in ObjC with very little clutter. It is not a book to learn from so much as a book to distill concepts into managable bites. Armed with this book and Programming in Objective-C will get you well on your way to programming in C, ObjC, Cocoa, and GNUstep (which is mainly what I am learning). All the other books get you deeper in the quagmire, yet for the most part assume that you the knowledge covered in these two books. This is the 'Ah Ha, now I see!' book when you have basic knowledge and need to get right to the point. I sometimes forget to look here first, usually to my irritation. Just buy it.
Also note that I am a big fan of all the 'in a nutshell' books as secondary refferences.

I'm attacking Objective-C from the perspective of a C# and former VB and Java developer, with some knowledge of C as well. I'm trying to actually read through the book as a fast jump-start into understanding the syntax, and although it does well for this, I found this book a bit frustrating at times. It leaves a few fundamental terms unexplained and then carries on using them as though the reader understands.

For example, what are namespaces in the context of Objective-C? In C#, they are simply explicitly declared container names. In Java, they are the same but also a file system hierarchy. In C, AFAIK, namespaces don't exist. But the book frequently says things like "classes are in the global namespace" and "categories are in their own namespace so they can have the same name as classes". What are namespaces in Obj-C? How on earth do you work with these namespaces??

Code examples from one to the next have nothing to do with the previous, so as you learn a new keyword, and you see a one-line syntax example, you have no other code to see it in context.. such as, hello, how on earth would I *use* that after invoking or declaring it?

It also failed to explain "field sections". One of the reasons I BOUGHT the book was because I didn't understand why some things are declared in braces in the interface declaration, and some things are not, but are still before @end. The book said nothing about these braces and what they're containing. It just said, oh hey, there's no semicolon after @end. (Over and over again, needlessly.) I only figured it out by inference--and am still not sure if I'm right--when I came across the "Category" sample code and where in sample code there's often an area in braces with fields there was instead the comment, "// No field section." Ah. So I guess whatever goes in braces is supposed to be fields.

The book is also obsolete. Objective-C 2.0 has since been released, and this book doesn't cover that. It's dated 2003.

So the book doesn't do a good job as a syntax tutorial like I hoped. But I'll admit that it came really, really close. If the book had these missing components, it would only be about 10-15% thicker I imagine, though, but I don't feel that there's any excuse as it's not just small, it's thin.

Probably the best book to read to learn Objective-C, if Apple's PDF on the language is not enough for you. Covers Objective-C both from Cocoa and non-Cocoa perspectives. Try Apple's PDF first, and if it's not enough to let you jump into one of the Cocoa programming books (which all mostly assume knowledge of C and Objective-C), then this book is recommended.