Book Image

The Java Workshop

By : David Cuartielles, Andreas Göransson, Eric Foster-Johnson
4 (2)
Book Image

The Java Workshop

4 (2)
By: David Cuartielles, Andreas Göransson, Eric Foster-Johnson

Overview of this book

Java is a versatile, popular programming language used across a wide range of industries. Learning how to write effective Java code can take your career to the next level, and The Java Workshop will help you do just that. This book is designed to take the pain out of Java coding and teach you everything you need to know to be productive in building real-world software. The Workshop starts by showing you how to use classes, methods, and the built-in Collections API to manipulate data structures effortlessly. You’ll dive right into learning about object-oriented programming by creating classes and interfaces and making use of inheritance and polymorphism. After learning how to handle exceptions, you’ll study the modules, packages, and libraries that help you organize your code. As you progress, you’ll discover how to connect to external databases and web servers, work with regular expressions, and write unit tests to validate your code. You’ll also be introduced to functional programming and see how to implement it using lambda functions. By the end of this Workshop, you’ll be well-versed with key Java concepts and have the knowledge and confidence to tackle your own ambitious projects with Java.
Table of Contents (20 chapters)

Inheritance in Java

Inheritance is a key principle of object-oriented programming. It entails the transfer of the existing structure of one class, including its constructor, variables, and methods, to a different class. The new class is called the child class (or subclass), while the one it's inheriting from is called the parent class (or superclass). We say that the child class extends the parent one. The child class is said to extend the parent class in the sense that it not only inherits whatever structures are defined by the parent, but it also creates new structures. The following example shows a parent class and how the child class extends it by adding a new method to it. We will take the Computer class we defined earlier as a parent and create a new class called Tablet, which is a type of computer.

Example05.java

20 class Tablet extends Computer {
21     // variables
22     private double screenSize;  ...