Book Image

Learn Java with Projects

By : Dr. Seán Kennedy, Maaike van Putten
5 (3)
Book Image

Learn Java with Projects

5 (3)
By: Dr. Seán Kennedy, Maaike van Putten

Overview of this book

Learn Java with Projects stands out in the world of Java guides; while some books skim the surface and others get lost in too much detail, this one finds a nice middle ground. You’ll begin by exploring the fundamentals of Java, from its primitive data types through to loops and arrays. Next, you’ll move on to object-oriented programming (OOP), where you’ll get to grips with key topics such as classes, objects, encapsulation, inheritance, polymorphism, interfaces, and more. The chapters are designed in a way that focuses on topics that really matter in real-life work situations. No extra fluff here, so that you get more time to spend on the basics and form a solid foundation. As you make progress, you’ll learn advanced topics including generics, collections, lambda expressions, streams and concurrency. This book doesn't just talk about theory—it shows you how things work with little projects, which eventually add up to one big project that brings it all together. By the end of this Java book, you’ll have sound practical knowledge of Java and a helpful guide to walk you through the important parts of Java.
Table of Contents (22 chapters)
1
Part 1: Java Fundamentals
9
Part 2: Object-Oriented Programming
15
Part 3: Advanced Topics

Set

The Set interface is part of the Java collections framework and represents a generally unordered collection of unique elements. This means that an element can only be in the set once. The commonly used implementations of the Set interface are HashSet, TreeSet, and LinkedHashSet. Let’s have a quick look at each.

HashSet

Let’s look at the most popular set first: HashSet. This is a widely used implementation of the Set interface based on a hash table. A hash table stores data in key-value pairs, enabling fast lookup by computing an item’s key hash. It provides constant-time performance for basic operations such as add, remove, and contains (checking whether a Set interface contains a certain value).

Constant-time complexity means that the time it takes to perform these operations does not increase when the number of elements in the set grows, assuming that the hash function used to distribute the elements among the buckets does its job well. We’...