Java tutorial
import java.util.SortedSet; import java.util.TreeSet; public class Main { public static void main(String[] args) { TreeSet<String> tSet = new TreeSet<String>(); tSet.add("1"); tSet.add("2"); tSet.add("3"); tSet.add("4"); tSet.add("5"); SortedSet sortedSet = tSet.headSet("3"); System.out.println("Head Set Contains : " + sortedSet); } }