sample code to demonstrate TreeSet class

// TreeSet Demo application

package collection;

import java.util.TreeSet;

public class TreeSetDemo {

    public static void main(String[] args) 
    {
        TreeSet l=new TreeSet();

        l.add(new Integer(30));

        l.add(new Integer(10));
        l.add(new Integer(40)); 
        //l.add(new Integer(30));duplicates are not added

        System.out.println(l);

    }
}


output:
[10, 30, 40]