How to use HashSet in Java with example ?.

Program to demonstrate how to implement HashSet class in java.util.*; package along with its operations :

package com.hubberspot.collections.example;

import java.util.*;

public class HashSetExample
{
 public static void main(String[] args)
 {
  HashSet hashset=new HashSet();
  hashset.add("B");
  hashset.add("A");
  hashset.add("F");

  System.out.println("The contents of set : "
     + hashset);
  
  hashset.add("E");
  hashset.remove("A");

  System.out.println("The contents of set : "
     + hashset);

  TreeSet treeSet = new TreeSet(hashset);

  System.out.println("The tree set contents : "
     + treeSet);
    
 } 
}

Output of the program :