Java Sets Unraveled: HashSet vs. TreeSet vs. LinkedHashSet

Photo by orbtal media on Unsplash

Introduction

In Java, the Set interface is a fundamental data structure that represents a collection of unique elements. A Set ensures that it contains no duplicate elements, making it perfect for scenarios where you need to store a collection of distinct values. In this blog, we will explore the concept of Sets, their common characteristics, delve into some of the most commonly used implementations of Sets in Java, and provide practical examples to showcase their usage and benefits.

Set Interface Overview

The Set interface in Java is part of the java.util package and extends the Collection interface. As with any set in mathematics, a Set in Java does not allow duplicate elements. When you attempt to add a duplicate element to a Set, the addition operation simply returns false, indicating that the element was not added.

Key characteristics of the Set interface:

• Does not maintain the order of elements (no positional access).
• Does not allow duplicate elements.
• Allows null elements (but only one null element, as duplicates are not allowed).

To use a Set, you must choose one of its implementations provided by Java.