Book Image

Java Fundamentals

By : Gazihan Alankus, Rogério Theodoro de Brito, Basheer Ahamed Fazal, Vinicius Isola, Miles Obare
Book Image

Java Fundamentals

By: Gazihan Alankus, Rogério Theodoro de Brito, Basheer Ahamed Fazal, Vinicius Isola, Miles Obare

Overview of this book

Since its inception, Java has stormed the programming world. Its features and functionalities provide developers with the tools needed to write robust cross-platform applications. Java Fundamentals introduces you to these tools and functionalities that will enable you to create Java programs. The book begins with an introduction to the language, its philosophy, and evolution over time, until the latest release. You'll learn how the javac/java tools work and what Java packages are - the way a Java program is usually organized. Once you are comfortable with this, you'll be introduced to advanced concepts of the language, such as control flow keywords. You'll explore object-oriented programming and the part it plays in making Java what it is. In the concluding chapters, you'll get to grips with classes, typecasting, and interfaces, and understand the use of data structures, arrays, strings, handling exceptions, and creating generics. By the end of this book, you will have learned to write programs, automate tasks, and follow advanced courses on algorithms and data structures or explore more advanced Java courses.
Table of Contents (12 chapters)
Java Fundamentals
Preface

Inheritance


In this section, we will have a look at another important principle of OOP, called inheritance. Inheritance in OOP has the same meaning as it has in English. Let's look at an example by using our family trees. Our parents inherit from our grandparents. We then inherit from our parents, and finally, our children inherit, or will inherit, from us. Similarly, a class can inherit the properties of another class. These properties include methods and fields. Then, another class can still inherit from it, and so on. This forms what we call an inheritance hierarchy.

The class being inherited from is called the superclass or the base class, and the class that is inheriting is called the subclass or the derived class. In Java, a class can only inherit from one superclass.

Types of Inheritance

An example of inheritance is a management hierarchy in a company or in the government:

Multiple inheritance is not directly supported in Java, but can be achieved by using interfaces, which will be covered...