TreeSet headSet(E toElement) method in java
import java.util.Iterator; import java.util.TreeSet; public class TreeSetHeadSetEToElementMethodExample { public static void main(String[] args) { TreeSet<Integer> ts = new TreeSet<Integer>(); TreeSet<Integer> hs = new TreeSet<Integer>(); ts.add(1); ts.add(2); ts.add(3); ts.add(4); ts.add(5); ts.add(6); // get values less than 5 hs = (TreeSet)ts.headSet(5); // create iterator Iterator<Integer> iterate = hs.iterator(); System.out.println("TreeSet data: "); while(iterate.hasNext()) { System.out.println(iterate.next() + " "); } } }