Working with SharedPreferences

Question

I want to know if some key-value pair already exists in shared preferences or not.

   sharedPref=getApplicationContext().getSharedPreferences("sharedf",Context.MODE_PRIVATE);
   editor=sharedPref.edit();
   editor.putString("secretKey",e1.getText().toString());
   editor.commit();

Now I want to check if secretKey already exists or not in the sharedprefrences.

Answer 1

It is simple. There is a method:

public abstract boolean contains (String key)

You can read it here:

http://developer.android.com/reference/android/content/SharedPreferences.html

Answer 2

You can do that in next way

sharedPref=getApplicationContext().getSharedPreferences("sharedf",Context.MODE_PRIVATE);
String secretKey = sharedPref.getString("secretKey", null);
if (null == secretKey) {
    // not exists
} else {
    // exists
}

Answer 3

     if (mPrefs.contains(SETTING_THEME)) {
                // read the value
                mThemeSettings = mPrefs.getString(SETTING_THEME, THEME_KEY_DEFAULT);
            } 
     // create a new "prefs entry" (first start, after installing the app)
     else mEditor.putString(SETTING_THEME, mThemeSettings).apply();

Answer 4

android: check if value exists in Shared Preferences

:-Check this

Try contains(String key) Accorting to the Javadocs,

Checks whether the preferences contains a preference. Returns true if the preference exists in the preferences, otherwise false.