I have this string array resource in /res/values/arrays.xml, for a ListPreference:
<string-array name="pref_font_size_entries">
<item>Small</item>
<item>Normal</item>
<item>Large</item>
<item>Extra Large</item>
</string-array>
If I want to add an extra list item (see the last <item>Huge</item>
) on larger screens, do I have to duplicate the entire declaration in /res/values-sw600dp/arrays.xml?
<string-array name="pref_font_size_entries">
<item>Small</item>
<item>Normal</item>
<item>Large</item>
<item>Extra Large</item>
<item>Huge</item>
</string-array>
Yes, you have to duplicate the entire definition of pref_font_size_entries
as they are not cumulative. Android picks the XML file which fits the resolution the best. If you have other definitions here or other XML files in /res/values which are the same for /res/values-sw600dp you don't need to duplicate those.