First. XML code
I recommend to learn this first because It fun to see it visualized.
Second. OnClickListener
Lot of YouTube tutorials uses this way to teach android Java. Basically In my word, this made it some understanding of interaction with a Java and XML code
Third. Onpause Method
By typing a line of code about "OnPause" method, it helps a lot for understanding a life cycle of android
Fourth. Learn the rest from YouTube
In this point and on I think book isnt needed so much for learning more. Actually just googling with watching from YouTube helps even more to understand in a stronger syntax
Thank you for reading my post and I hope you guys have enjoyed it. I am very excited to hear from you guys
-Edd Park-