Android - Sharedpreference Converting To Double

Basically i have a valued saved into shared preference as a string. I am retrieving the value saved, and am trying to use it in a calculation. How can i convert this so that it is

Solution 1:

You can parse the string as a double:

SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());

String weight =  sharedPreferences.getString("storednewweight", "");
Double newweight = Double.parseDouble(weight);
newweight = newweight + 5;

//saves value into sharedpreference
savePreferences("storednewweight", (Double.toString(newweight)));

Solution 2:

How can i convert this so that it is seen as a double instead of a string?

A) If you don't need the double precision, use floats: getFloat and putFloat.

B) Parse the string as a double then save the double as a string again.

Solution 3:

It can be saved as long like how I wrote it down:

Double to Long:

Double.doubleToRawLongBits(double);

Long to Double:

Double.longBitsToDouble(defaultLongValue);

EDIT:

SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
Long newweightTemp =  sharedPreferences.getLong("storednewweight", 0L);
Double newWeight = Double.longBitsToDouble(newweightTemp );
newweight = newweight + 5;
//saves value into sharedpreference
sharedPreferences.edit().putLong("storednewweight", Double.doubleToRawLongBits(newWeight)).apply();

Something like that should do it.