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

Mastering advanced encapsulation

The simple maxim of “private data, public methods” (where the public methods manipulate the data) goes a long way to ensuring proper encapsulation of your data. However, you are not completely safe just yet. In this section, we will review Java’s call by value principle, which is used when passing arguments to and returning values from methods. We will examine how this can present a subtle issue. Lastly, we will examine how to protect your code from encountering this issue in the first place.

Call By value revisited

In Chapter 7, we discussed how, when passing arguments to methods, Java’s call by value mechanism creates copies of those arguments. We saw the need to be aware that when the argument is a reference, such as to an array, the called method can now manipulate the array object that the caller method is looking at.

Similarly, when a method is returning something, call by value applies again. In other words...