Saving Data on Android

Key points
•
SharedPreferences
 are a great way to store 
small bits of data
 for an app.
• User—specific app configuration data is often stored in 
SharedPreferences
.
•
Preferences
 are also stored in an app's default 
SharedPreferences
, but they are 
not to be confused with each other.
•
SharedPreferences
 are not a good choice to store structured data, like various 
entities, use a database for that.
•
SharedPreferences
 are organized in 
key—value pairs
 that are ultimately written 
out to a file in .xml format.
• Each app has its own 
SharedPreferences
. When the app is uninstalled or the data 
is deleted, these stored values are wiped away.
• You can create custom-named 
SharedPreferences
 files and store user's choices 
in them.
Saving Data on Android
Chapter 2: Shared Preferences
raywenderlich.com
47

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• To edit 
SharedPreferences
, you first have to fetch its 
Editor
, by calling 
edit()
.
• When writing 
SharedPreferences
, use 
apply()
 instead of 
commit()
 to perform 
an asynchronous, thread—safe write.