My local bookstore had a discount on all programing books so I went out and scanned some barcodes, and got the one with the best reviews. I got home and discovered it's made for ipad os 3.2. I'm wondering, is it worth using this book to learn how to program for ipad (i have some experience with java, none with objective c nor cocoa)? Or should I just return it and try to find one online for 4.2? Thanks for any/all help!