I know it sounds like a pretty silly question, but I'm starting now in the programming world (focused on mobile).
When I create an app it gets all the functions within the Activities, so I never know when I should take methods and attributes of the class and separate them. ah! this also serves to organize packages and classes
Thank you for your attention.
It depends,
Each activity has its own lifecycle, which may or may not affect the app life cycle.
I recommend reading Activity .
And then there are fragments, which helps the app to be split by blocks of the app itself, which can then reuse in various activities. I recommend reading Fragment .
And then, following Java standards, you should program following the POO paradigm, creating classes to represent various things (objects or abstract things)
Based on the concept that a classe is a structure that abstracts a set of objects with similar characteristics it may contain methods or attributes. So you can have a class to represent an entity of your bank for example or a class that contains methods to perform operations in your bank. Before you start coding I suggest giving a good read on a material about POO
Concepts of Object Orientation - Ufpa
Object Oriented Programming - Unicamp
