How to quit android application programmatically

Question

I Found some codes for quit an Android application programatically. By calling any one of the following code in onDestroy() will it quit application entirely?

Answer 1

You had better use finish() if you are in Activity, or getActivity().finish() if you are in the Fragment.

If you want to quit the app completely, then use:

getActivity().finish();
System.exit(0);