OCP Oracle Certified Professional Java SE 11 Programmer II Study Guide

Exam 1Z0-816 and Exam 1Z0-817

Scott Selikoff, Jeanne Boyarsky

• Editorial: Sybex
• Año: 2020
• ISBN:
  9781119617587
• Edición: 1
• Categoría: Computer Science
• Categoría: Software Development

This OCP Oracle Certified Professional Java SE 11 Programmer I Study Guide: Exam 1Z0-815 and the Programmer II Study Guide: Exam 1Z0-816 were published before Oracle announced major changes to its OCP certification program and the release of the new Developer 1Z0-819 exam. No matter the changes, rest assured both of the Programmer I and II Study Guidescover everything you need to prepare for and take Exam 1Z0-819. If you've purchased one of the Programmer Study Guides, purchase the other one and you'll be all set. NOTE: The OCP Java SE 11 Programmer I Exam 1Z0-815 and Programmer II Exam 1Z0-816 have been retired (as of October 1, 2020), and Oracle has released a new Developer Exam 1Z0-819 to replace the previous exams.The Upgrade Exam 1Z0-817 remains the same.

Thecompletely-updated preparation guide for the new OCP Oracle Certified Professional Java SE 11 Programmer II exam—covers Exam 1Z0-816

Java, a platform-independent, object-oriented programming language, is used primarily in mobile and desktop application development. It is a popular language for client-side cloud applications and the principal language used to develop Android applications. Oracle has recently updated its Java Programmer certification tracks for Oracle Certified Professional.

OCP Oracle Certified Professional Java SE 11 Programmer II Study Guide ensures that you are fully prepared for this difficult certification exam. Covering 100% of exam objectives, this in-depth study guide provides comprehensive coverage of the functional-programming knowledge necessary to succeed. Every exam topic is thoroughly and completely covered including exceptions and assertions, class design, generics and collections, threads, concurrency, IO and NIO, and more. Access to Sybex's superior online interactive learning environment and test bank—including self-assessment tests, chapter tests, bonus practice exam questions, electronic flashcards, and a searchable glossary of important terms—provides everything you need to be fully prepared on exam day. This must-have guide:

• Covers all exam objectives such as inheriting abstract classes and interfaces, advanced strings and localization, JDBC, and Object-Oriented design principles and patterns
• Explains complex material and reinforces your comprehension and retention of important topics
• Helps you master more advanced areas of functional programming
• Demonstrates practical methods for building Java solutions

OCP Oracle Certified Professional Java SE 11 Programmer II Study Guide will prove invaluable for anyone seeking achievement of this challenging exam, as well as junior- to senior-levelprogrammers who uses Java as their primary programming language.

Chapter 1
Java Fundamentals

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OCP EXAM OBJECTIVES COVERED IN THIS CHAPTER:

• Java Fundamentals
  • Create and use final classes
  • Create and use inner, nested and anonymous classes
  • Create and use enumerations
• Java Interfaces
  • Create and use interfaces with default methods
  • Create and use interfaces with private methods
• Functional Interface and Lambda Expressions
  • Define and write functional interfaces
  • Create and use lambda expressions including statement lambdas, local-variable for lambda parameters

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Welcome to the first chapter on your road to taking the 1Z0-816 Programmer II exam! If you've recently taken the 1Z0-815 Programmer I exam, then you should be well versed in class structure, inheritance, scope, abstract types, etc. If not, you might want to review your previous study materials. The exam expects you to have a solid foundation on these topics. You can also read our 1Z0-815 exam book, OCP Oracle Certified Professional Java SE 11 Programmer I Study Guide: Exam 1Z0-815 (Sybex, 2019).

In this chapter, we are going to expand your understanding of Java fundamentals including enums and nested classes, various interface members, functional interfaces, and lambda expressions. Pay attention in this chapter, as many of these topics will be used throughout the rest of this book. Even if you use them all the time, there are subtle rules you might not be aware of.

Finally, we want to wish you a hearty congratulations on beginning your journey to prepare for the 1Z0-816 Programmer II exam!

Taking the Upgrade Exam?

If you're studying for the 1Z0-817 Upgrade Exam, please consult the list of objectives in the introduction to know which topics to study. For these readers, we have also written a specialized Appendix A, “The Upgrade Exam,” which covers additional objectives that are not part of the 1Z0-816 exam, such as var and module creation. If you're taking the 1Z0-817 exam, you should read Appendix A before reading this chapter.

Applying the final Modifier

From your previous study material, you should remember the final modifier can be applied to variables, methods, and classes. Marking a variable final means the value cannot be changed after it is assigned. Marking a method or class final means it cannot be overridden or extended, respectively. In this section, we will review the rules for using the final modifier.

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If you studied final classes for the 1Z0-815 exam recently, then you can probably skip this section and go straight to enums.

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Declaring final Local Variables

Let's start by taking a look at some local variables marked with the final modifier:

private void printZooInfo(boolean isWeekend) {  final int giraffe = 5;  final long lemur;  if(isWeekend) lemur = 5;  else lemur = 10;  System.out.println(giraffe+" "+lemur); } 

As shown with the lemur variable, we don't need to assign a value when a final variable is declared. The rule is only that it must be assigned a value before it can be used. Contrast this with the following example:

private void prin...