What would you say is the main advantage of developing an application for the Android platform as opposed to the Iphone platform ?
I'm thinking in terms of functionality that one can do but the other can't .
My book isn't really about Android -- it has to do with setting the stage for jumping into Android development by providing a thorough understanding of the Java language and foundational APIs (such as the collections framework) -- so I can't comment from the perspective of an expert Android developer (although I intend to change that over the next few months).
When I compare Android with iPhone, these two items are what occur to me:
1) cost -- I believe that it is cheaper to jump into Android than into iPhone programming from a financial perspective because you don't need to purchase a Mac (if you don't already have one) on which to perform development tasks. Correct me if I'm wrong, but I believe that you also need to buy an iPhone to try out your iPhone apps, and that you also have to purchase the SDK. In contrast, Android provides a free SDK and a free emulator on which to try out your apps.
2) learning curve -- I believe it is easier to learn Java than Objective-C.
I wish I could comment on functionality but I don't have the specifics. However, I believe that as Android continues to grow, it will keep up with iPhone in terms of capabilities.