Convert an ArrayList to HashSet
import java.util.ArrayList; import java.util.HashSet; import java.util.List; import java.util.Set; public class Main { public static void main(String[] args) { List<String> myList = new ArrayList<String>(); myList.add("A"); myList.add("B"); myList.add("C"); myList.add("D"); Set<String> mySet = new HashSet<String>(myList); for (Object theFruit : mySet) System.out.println(theFruit); } } /* D A B C */