How to declare global variables in Android?

Question

I am creating an application which requires login. I created the main and the login activity.

In the main activity onCreate method I added the following

Answer 1

If some variables are stored in sqlite and you must use them in most activities in your app. then Application maybe the best way to achieve it. Query the variables from database when application started and store them in a field. Then you can use these variables in your activities.

So find the right way, and there is no best way.