Permanent Data Storage - Shared Preferences

Android-SharedPreferences.java

       /*
      Permanent Data Storage
        There are different ways of storing data on the app, the most simple one iscalled
        Shared Preferences.
            this is a way of storing just very simple short items of data like username or ideally
            a preference that user has choosen for the app.
            it is great for storing short information.
      */

        SharedPreferences sharedPreferences = this.getSharedPreferences("com.mohammadsamandari.sharedpreferences", Context.MODE_PRIVATE);
        //  The first bit of information is the apps name
        //  The second part defines that only this app is going to access this shared preferences.

        //  To save a item into shared preferences:
        sharedPreferences.edit().putString("username", "lord").apply();

        //  to get back information out of shared preferences.
        String username = sharedPreferences.getString("username", "DEFAULT_VALUE_IN_CASE_NOT_AVAILABLE");