HashSet

HashSet hs = new HashSet();

hs.add("apple");

hs.add("banana");

hs.add("cidar");

hs.add("apple");

System.out.println(hs);

if (hs.contains("strawberry")==true) 

System.out.println("It has an apple");

Iterator it = hs.iterator();

while (it.hasNext()) {

Object obj = it.next();

System.out.println(obj);

}

HashSet hs1 = (HashSet) hs.clone();

hs1.add("melon");

hs1.remove("apple");

System.out.println("hs1"+hs1);

System.out.println("hs"+hs);

HashSet hs2 = (HashSet) hs.clone();

hs2.addAll(hs1);

System.out.println(hs2);

hs2.retainAll(hs);

System.out.println(hs2);

}

}