Iterating over this set requires time proportional to the sum of the HashSet instance's size (the number of elements) plus the "capacity" of the backing HashMap instance (the number of buckets).

This example creates two HashSet<T> objects and populates them with even and odd numbers, respectively. A third HashSet<T> object is created from the set that contains the even numbers.

Apr 24, 2026 · HashSet in Java implements the Set interface of the Collections Framework. It is used to store the unique elements, and it doesn't maintain any specific order of elements.

Java HashSet A HashSet is a collection of elements where every element is unique. It is part of the java.util package and implements the Set interface.

Jul 3, 2025 · In this article, we outlined the utility of a HashSet, its purpose as well as its underlying working. We saw how efficient it is in terms of usability given its constant time performance and …

Here is a great example: How to implement ConcurrentHashSet in .Net The only drawback of this solution is that the type HashSet<T> doesn't officially concurrent access, even for reading …

Mar 27, 2026 · In simple terms, the hierarchy follows this order: Iterable → Collection → Set → AbstractSet → HashSet. A HashSet is used to store a collection of unique elements, meaning it does …

5 days ago · A practical guide to Java HashSet: add unique values, fast contains checks, remove duplicates from a list, and union, intersection, and difference - with runnable examples.

In this tutorial, we will learn about the Java HashSet class. We will learn about different hash set methods and operations with the help of examples.

HashSet is a part of the Java Collections Framework and provides a collection that uses a hash table for storage. It allows for fast insertion, deletion, and lookup of elements.