Set <String> set = sharedPref.getStringSet(dayName, null);

Set <String> set = sharedPref.getStringSet(dayName, null);
List<String> list = new ArrayList<String>(set);
String[] objects = list.toArray();

Set<String> set = new HashSet<String>();
set.add("object 1");
set.add("object 2");
set.add("object 3");
set.add("object 4");

String[] array = null;

array = set.toArray(new String[set.size()]);

for(String item:array){
    System.out.println(item);
}