Get Head Set from Java TreeSet example

This Java Example shows how to get the portion of TreeSet containing the values less than the specified value using headSet method of Java TreeSet class.

import java.util.SortedSet;
import java.util.TreeSet;

public class GetHeadSetFromTreeSetExample {

	public static void main(String[] args) {

		// create TreeSet object
		TreeSet tSet = new TreeSet();

		// add elements to TreeSet
		tSet.add("1");
		tSet.add("3");
		tSet.add("2");
		tSet.add("5");
		tSet.add("4");

		/**
		 * To get a Head Set from Java TreeSet use, SortedSet headSet(Object
		 * fromElement) method of Java TreeSet class.
		 * 
		 * This method returns the portion of TreeSet containing elements less
		 * than fromElement.
		 * 
		 * Please note that, the SortedSet returned by this method is backed by
		 * the original TreeSet. So any changes made to SortedSet will be
		 * reflected back to original TreeSet.
		 **/

		SortedSet sortedSet = tSet.headSet("3");

		System.out.println("Head Set Contains : " + sortedSet);

	}
}

The output is:


Head Set Contains : [1, 2]