Convert Collection to Array

1. Convert Set to Array of String
         final HashMap<String, String> orderingOptionMap = new HashMap<String, String>();
         orderingOptionMap.put("1", "Name: A-Z");
         orderingOptionMap.put("2", "Name: Z-A");
         orderingOptionMap.put("3", "Age: Ascending");
         orderingOptionMap.put("4", "Age: Descending");

          String[] orderingOption =  orderingOptionMap.keySet().toArray(new String[orderingOptionMap.size()]);

           

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