How to Fix the "String cannot be cast to int" Error in Android Preferences

What does the "String cannot be cast to int" error mean in Android Preferences and how can I resolve it?

SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
int myPreferenceValue = sharedPreferences.getInt("myKey", 0); // Error could occur here if "myKey" value is stored as a String.

In Android, when dealing with SharedPreferences, the "String cannot be cast to int" error typically arises when there is an attempt to retrieve an integer value from SharedPreferences that has been stored as a String. This situation can typically occur if the data type in the preferences file does not match the requested type during retrieval.

// Example of saving an integer
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putInt("myKey", 123);
editor.apply();

// Example of retrieving an integer
int myPreferenceValue = sharedPreferences.getInt("myKey", 0); // This is correct usage

Causes

• A value that was intended to be saved as an integer was actually saved as a String.
• Incorrect usage of SharedPreferences methods when saving to or retrieving from preferences.

Solutions

• Ensure that when you save values to SharedPreferences, you are saving the right data type. Use `putInt()` for integers and `putString()` for strings accordingly.
• When retrieving values, use `getString()` if the saved type is a String or ensure your stored value is of the correct type when using `getInt()`.
• Check and verify the preferences XML file manually to understand what type of data was saved for the specific key.

Mistake: Trying to retrieve a saved String value using `getInt()`.

Solution: Use `getString()` to retrieve values saved as Strings.

Mistake: Not ensuring the data type saved in preferences matches what you are trying to retrieve.

Solution: Double-check the data types being saved and retrieved to avoid casting errors.