Ionic 2 versus Ionic 3

In this book, all the examples have been written with Ionic 2 in mind. Having said that, if you are using Ionic 3 to develop your Ionic apps, there should not be much of a change in the code. One key difference you will note in all the scaffolded apps is the introduction of IonicPage decorator and IonicPage Module.

You can always refer to the Ionic documentation to get more information on the latest version of these APIs.