Book Image

Java 9 with JShell

By : Gaston C. Hillar
Book Image

Java 9 with JShell

By: Gaston C. Hillar

Overview of this book

The release of Java 9 has brought many subtle and not-so-subtle changes to the way in which Java programmers approach their code. The most important ones are definitely the availability of a REPL, known as JShell, which will make experiments and prototyping much more straightforward than the old IDE-based project-led approach. Another, more subtle change can be seen in the module system, which will lead to more modularized, maintainable code. The techniques to take full advantage of object-oriented code, functional programming and the new modularity features in Java 9 form the main subjects of this book. Each chapter will add to the full picture of Java 9 programming starting out with classes and instances and ending with generics and modularity in Java.
Table of Contents (23 chapters)
Java 9 with JShell
Credits
About the Author
Acknowledgement
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Test your knowledge


  1. Which of the following lines declares an instance method that cannot be overridden in any subclass:

    1. public void talk(): final {

    2. public final void talk() {

    3. public notOverrideable void talk() {

  2. We have an abstract superclass named Shape. The Circle class is a subclass of Shape and is a concrete class. If we create an instance of Circle named circle, this instance will also be:

    1. An instance of Shape.

    2. A subclass of Circle.

    3. An abstract superclass of Circle.

  3. In UML diagrams, class names that use italic text format indicate that they are:

    1. Concrete classes.

    2. Classes that override at least one member inherited from its superclass.

    3. Abstract classes.

  4. Which of the following lines declares a class that cannot be subclassed:

    1. public final class Dog extends VirtualAnimal {

    2. public final class Dog subclasses VirtualAnimal {

    3. public final Dog subclasses VirtualAnimal {

  5. Which of the following lines declares a concrete class named Circle that can be subclassed and whose superclass is the Shape abstract...