If you keep it like that:
```xml
    <string-array name="someValues">
        <item>@style/Theme.Sherlock</item>
    </string-array>
```

then you can just
```java
 int themeID = sharedPrefs.getInteger("preferencesKeyTheme", R.style.theme_default);
```
and
```java
setTheme(themeID); 
```

It's written from memory, but you'll get what I mean.