SharedPreferences & Its Uses

What are SharedPreferences?

SharedPreferences are key-value group of general data types that are saved in a folder  
within an apps file structure. You can access this file from any place within the app to 
either put data into the file or take data out of the file. You can’t access the file from 
another app so it is secure from that point of view.

Where would you use SharedPreferences?

You would for example use SharedPreferences in a game where you would save the
 user’s name, high score, and state of the game when they logged off. Then the next time 
they log in, their score and game level would be recover from the desire file and they will 
continue the game from where they ended it when they logged off.

Save your data in a single or multiple SharedPreferences files

You can save your desire data in a single file or multiple files, based on your needs. The 
process is the same object for the SharedPreferences object that you get.In the case of a
 single file, call getPreferences() to get a SharedPreferences object and for multiple files, 
call getSharedPreferences() and pass it a name for the file as a parameter.

• getPreferences() - for Activity level preferences. Each action will have its own 

preference file

• getSharedPreferences() - for application-level preferences. You can access to 

 preference file from anywhere in the application

 

Retrieving the data

Once you have the SharedPreferences object, you can use a number of get<type> method 
for restore the values.

Uses of Preference share

A Shared Preference file is a simple XML file which prefer your application. You can store
 key-value pairs of data which your app requires often.

Most often, it can be used as some sort of cache/cookie which will be useful when the
 user's detail/action is to be retained when he comes back to use the application.

Some of the common uses of shared preferences :

1. If any user wants to  use shared preferences to check login, and if the user is logged in
 to your application you can direct that to the dashboard and if not, show them the login
 page.

2. Show the first time users the demo of your app. Most of the apps today shows the users 
who opens the app for the first time about the app, how to use it and what is where kind 
of things.

3. Some information which is required across different activities and it is hard to pass 
through design and not important enough to store in DB.

Shared preference are mostly for temporary storage in Android . We are 
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