Java HashSet Class & Set Interface

Before we learn about Java hashSet class, we will learn about the Set interface. Because the HashSet class implements Java Collection’s Set interface. The Set Interface ensures the implementing class to hold uniqueness in the collection. Means, it does not allow duplicate items. In Java Collection framework, the below classes implement the Set interface:

1. HashSet
2. EnumSet
3. TreeSet

There were other classes as well. But here we listed frequently used ones. In this example, we will explore about the HashSet collection class.