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

Map

Another member of the collections framework is the Map interface. This interface represents a collection of key-value pairs. Keys are unique, while values can be duplicated. That’s why we use the key to add and access the key-value pairs in a map. The commonly used implementations of the Map interface that we’ll discuss are HashMap and TreeMap.

HashMap

Probably the most popular one is HashMap. This is a widely used implementation of the Map interface that’s based on a hash table. Just like HashSet, it provides constant-time performance for basic operations. However, it does not guarantee any specific order of the keys. HashMap is suitable for situations where you need fast lookups and modifications, such as storing configuration settings or counting word occurrences in a piece of text. When the order is important, we can use TreeMap.

TreeMap

TreeMap is an implementation of the Map interface that’s based on a tree. It maintains key-value pairs...