Java Challengers
$12.99
Minimum price
$19.99
Suggested price

Java Challengers

Master the Java Fundamentals with fun Java Code Challenges! Become a Java Challenger!

About the Book

To get the best jobs and create high-quality code, you need to know Java very well. The Java Challenges book is a powerful way for you to master the fundamentals of Java by having fun with code challenges so you become a well-prepared highly employable Java Challenger Developer.

This book contains more than 70 well-elaborated Java Challenges that will help you break your limits on your Java skills. Want to challenge yourself and become better? The Java Challenges is the book for you!

  • Share this book

  • Categories

    • Java
    • Computers and Programming
    • Computer Science
    • Functional Programming
  • Feedback

    Email the Author(s)

About the Author

Rafael Chinelato del Nero
Rafael Chinelato del Nero

Rafael del Nero is a Java Champion & Oracle Groundbreaker Ambassador, creator of the Java Challengers initiative and quiz master in Oracle Dev Gym, is the author of "Golden Lessons - 100 Insights to Overcome Life's Challenges and Achieve Your Career Dreams." Rafael believes there are many techniques involved in creating high-quality software that developers are often unaware of. His life's purpose is to help Java developers use better programming practices to code quality software for stress-free projects with fewer bugs.

Table of Contents

  • Foreword
    • Jeanne Boyarsky
  • 1 Introduction
    • 1.2 Why Java?
    • 1.3 What kinds of concepts are in this book?
    • 1.4 Who is this book for?
    • 1.5 What are the Java Challenges?
    • 1.6 Disclaimer about the Java Challenges
    • 1.7 Java versioning and tools
    • 1.8 Will this book prepare you for the software development market?
  • 2 Variable types and flow control (Review)
    • 2.1 A Brief Review about Algorithms
    • 2.2 Arithmetic Operators
    • 2.3 Flow Control
    • 2.4 Loops
    • 2.5 Arrays
    • 2.6 Local variable restrictions
    • 2.7 Candy Price Code Challenge
    • 2.8 Summary
  • 3 Basic object-oriented programming (Review)
    • 3.1 Classes
    • 3.2 Methods
    • 3.3 The Keyword this
    • 3.4 Constructors
    • 3.5 Object references
    • 3.6 Arrays are objects in Java
    • 3.7 Bank Deposit/Withdraw Challenge
    • 3.8 Summary
  • 4 Encapsulation access modifiers, and package structure
    • 4.1 Programming to interfaces
    • 4.2 What are and how to use getters and setters?
    • 4.3 The Builder Design Pattern
    • 4.4 Organizing Packages in a Real Project
    • 4.5 Encapsulation Patterns
    • 4.6 Access Modifiers
    • 4.7 Inner Class
    • 4.8 The static keyword
    • 4.9 Instance and static block
    • 4.10 Small Real-World Project Challenge
    • 4.11 Summary
  • 5 Overloading
    • 5.1 Overloading basics
    • 5.2 Wrappers and autoboxing
    • 5.3 Varargs
    • 5.4 Overloading Real-World Usage Challenge
    • 5.5 Summary
  • 6 Inheritance and Polymorphism
    • 6.1 When to use inheritance
    • 6.2 Every Class is an Object
    • 6.3 Checking the type of an object
    • 6.4 The toString method
    • 6.5 Access modifiers and inheritance
    • 6.6 Object composition
    • 6.7 Multiple inheritance in Java
    • 6.8 Using super to access a parent class’s methods
    • 6.9 Constructors and inheritance
    • 6.10 Class casting
    • 6.11 Preventing inheritance
    • 6.12 Abstract classes
    • 6.13 Factory Method Strategy Discount Real-world Challenge
    • 6.14 Summary
  • 7 Interfaces
    • 7.1 Interfaces and Polymorphism
    • 7.2 Covariant return types
    • 7.3 Default methods
    • 7.4 Abstract classes vs. interfaces
    • 7.5 Static methods in interfaces
    • 7.6 Simulating multiple inheritance with default methods
    • 7.7 Private methods in interfaces
    • 7.8 Command Design Pattern Challenge
    • 7.9 Summary
  • 8 Exceptions
    • 8.1 Checked and unchecked exceptions
    • 8.2 Stack Trace
    • 8.3 Handling or Declaring Checked Exceptions
    • 8.4 try, catch, finally
    • 8.6 try with resources
    • 8.7 Multi catch
    • 8.8 Creating a customized exception
    • 8.9 Throw early, catch late
    • 8.10 Real World Exception Creation Challenge
    • 8.11 Summary
  • 9 Lambdas and Functional Interfaces
    • 9.1 What is Lambda?
    • 9.2 Functional Interfaces
    • 9.3 Method Reference
    • 9.4 Lambda Method Reference Matcher Challenge:
    • 9.5 Summary
  • 10 Optional
    • 10.1 Wrapping a value into Optional
    • 10.2 isPresent and isEmpty
    • 10.3 Optional Antipatterns
    • 10.4 ifPresent and ifPresentOrElse
    • 10.6 Handling Exceptions with orElseThrow
    • 10.7 Transforming Optional Data
    • 10.8 Final Yoshi Food Optional Challenge
    • 10.9 Summary
  • 11 Generics and Object Comparison
    • 11.1 Comparing objects with equals and hashcode
    • 11.2 Generics
    • 11.4 Upper and Lower Bound Generics
    • 11.5 Summary
  • 12 Collections
    • 12.1 Collections API
    • 12.2 List
    • 12.3 ArrayList
    • 12.4 Vector
    • 12.5 Deque & Stack
    • 12.6 ConcurrentModificationException
    • 12.7 Using Comparable
    • 12.8 Set
    • 12.9 HashSet
    • 12.10 LinkedHashSet
    • 12.11 TreeSet
    • 12.12 Map
    • 12.16 TreeMap
    • 12.17 Elements Searching
    • 12.18 Summary
  • 13 Streams
    • 13.1 Streams Basic Principles
    • 13.2 Creating a Stream
    • 13.3 Intermediate VS Terminal Operation Methods
    • 13.4 Intermediate Operations
    • 13.5 Terminal Operations
    • 13.6 Parallelizing Data Processing with parallel()
    • 13.7 Collecting Data with collect()
    • 13.8 Collectors.groupingBy
    • 13.9 Summary
  • 14 Newest Features of Java
    • 14.1 Java Release Strategy
    • 14.2 Introduction to Modules
    • 14.3 Java JDK Base Modules
    • 14.4 Named application module
    • 14.5 Unnamed module
    • 14.6 Exporting Packages from Module
    • 14.7 Requiring a Module
    • 14.8 Exporting a service with provides with
    • 14.9 Module Reflection Access
    • 14.10 Star Trek Planets Module Special Challenge
    • 14.11 Reserved word var
    • 14.12 New switch case statement
    • 14.13 Using Pattern Matching Type Checks Java 15
    • 14.14 Using record
    • 14.15 Using Sealed classes Java 15
    • 14.16 Text Blocks Java 15
    • 14.17 Summary
  • 15 Concurrency Fundamentals
    • 15.1 Fundamentals of Concurrency
    • 15.2 Thread
    • 15.3 Using Thread sleep
    • 15.4 Using join
    • 15.5 non-daemon and daemon Thread
    • 15.6 Using interrupt
    • 15.7 Race Condition
    • 15.8 Mutual Exclusion (Mutex)
    • 15.9 Using wait and notify
    • 15.10 Summary
  • 16 Advanced Concurrency
    • 16.1 ReentrantLock Basics
    • 16.2 Atomic Variables
    • 16.3 The volatile keyword
    • 16.4 The happens-before Rule
    • 16.5 CompletableFuture
    • 16.6 Threadpool with Executors
    • 16.7 ConcurrentHashMap
    • 16.8 ConcurrentSkipListMap
    • 16.9 Producer Consumer with BlockingQueue
    • 16.10 Summary
  • 17 Next Steps
    • 17.1 Other important Java features
    • 17.2 Practicing Clean Code
    • 17.3 Tendencies of the market
    • 17.4 Getting prepared for interviews
    • 17.5 Strategies to Stay Sharp
    • 17.6 Learn more about negotiation
    • 17.7 Do you want more?

The Leanpub 60 Day 100% Happiness Guarantee

Within 60 days of purchase you can get a 100% refund on any Leanpub purchase, in two clicks.

Now, this is technically risky for us, since you'll have the book or course files either way. But we're so confident in our products and services, and in our authors and readers, that we're happy to offer a full money back guarantee for everything we sell.

You can only find out how good something is by trying it, and because of our 100% money back guarantee there's literally no risk to do so!

So, there's no reason not to click the Add to Cart button, is there?

See full terms...

80% Royalties. Earn $16 on a $20 book.

We pay 80% royalties. That's not a typo: you earn $16 on a $20 sale. If we sell 5000 non-refunded copies of your book or course for $20, you'll earn $80,000.

(Yes, some authors have already earned much more than that on Leanpub.)

In fact, authors have earnedover $13 millionwriting, publishing and selling on Leanpub.

Learn more about writing on Leanpub

Free Updates. DRM Free.

If you buy a Leanpub book, you get free updates for as long as the author updates the book! Many authors use Leanpub to publish their books in-progress, while they are writing them. All readers get free updates, regardless of when they bought the book or how much they paid (including free).

Most Leanpub books are available in PDF (for computers) and EPUB (for phones, tablets and Kindle). The formats that a book includes are shown at the top right corner of this page.

Finally, Leanpub books don't have any DRM copy-protection nonsense, so you can easily read them on any supported device.

Learn more about Leanpub's ebook formats and where to read them

Write and Publish on Leanpub

You can use Leanpub to easily write, publish and sell in-progress and completed ebooks and online courses!

Leanpub is a powerful platform for serious authors, combining a simple, elegant writing and publishing workflow with a store focused on selling in-progress ebooks.

Leanpub is a magical typewriter for authors: just write in plain text, and to publish your ebook, just click a button. (Or, if you are producing your ebook your own way, you can even upload your own PDF and/or EPUB files and then publish with one click!) It really is that easy.

Learn more about writing on Leanpub