private void toPreference() { preferences.favoriteCharacter = characterName.getText().toString(); preferences.dark = dark.isChecked(); preferences.light = light.isChecked(); int checkedRadioButtonId = droid.getCheckedRadioButtonId(); if (checkedRadioButtonId >= 0) preferences.droid = DROIDS.indexOf(checkedRadioButtonId); int checkedSpaceShipId = spaceship.getCheckedRadioButtonId(); if (checkedSpaceShipId >= 0) preferences.spaceship = SPACESHIPS.indexOf(checkedSpaceShipId); preferences.apply(); }