Saving Data on Android

Note
: They are also the location where app 
Preferences
 are saved. However, 
the two should not be confused with one another.
The first step to using 
SharedPreferences
 is obtaining a reference to the app—
specific file, let's see how to do that!
GeTng a reference to the 
SharedPreferences file
Depending on how you want to use 
SharedPreferences
, there are different ways to 
access or create the 
SharedPreferences
 file:
•
getSharedPreferences()
 can be called from any 
Context
 in your app and allows 
you to specify a name for the file. It is handy if you need multiple 
SharedPreferences
 files with different names.
•
getPreferences()
 is called from an 
Activity
 and does not allow you to specify a 
file name because it uses the default class name of that 
Activity
. It is handy if 
you need to create different preference files for different activities.
•
getDefaultSharedPreferences()
 is used for app settings and preferences at the 
app level
, and returns the default prefs file for the entire app. You can use this to 
store data that is useful for your entire app, or features you set up every time a 
user starts your app.
But getting preferences is only half of the work. You still need to read and write data 
to the prefs.