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Java Challengers

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

Rafael Chinelato del Nero

Master the Java fundamentals and have a lot of fun solving the Java code Challenges of this book. You will see if you really know core Java concepts well. There are more than 70 well-elaborated Java code Challenges for you to challenge yourself and refine your Java skills to the very best so you can get rid of bugs far more easily.

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About

About

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!

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JavaComputers and ProgrammingComputer ScienceFunctional Programming

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Author

About the Author

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.

Leanpub Podcast

Episode 270

An Interview with Rafael Chinelato del Nero

Contents

Table of Contents

Foreword

  1. Jeanne Boyarsky

1 Introduction

  1. 1.2 Why Java?
  2. 1.3 What kinds of concepts are in this book?
  3. 1.4 Who is this book for?
  4. 1.5 What are the Java Challenges?
  5. 1.6 Disclaimer about the Java Challenges
  6. 1.7 Java versioning and tools
  7. 1.8 Will this book prepare you for the software development market?

2 Variable types and flow control (Review)

  1. 2.1 A Brief Review about Algorithms
  2. 2.2 Arithmetic Operators
  3. 2.3 Flow Control
  4. 2.4 Loops
  5. 2.5 Arrays
  6. 2.6 Local variable restrictions
  7. 2.7 Candy Price Code Challenge
  8. 2.8 Summary

3 Basic object-oriented programming (Review)

  1. 3.1 Classes
  2. 3.2 Methods
  3. 3.3 The Keyword this
  4. 3.4 Constructors
  5. 3.5 Object references
  6. 3.6 Arrays are objects in Java
  7. 3.7 Bank Deposit/Withdraw Challenge
  8. 3.8 Summary

4 Encapsulation access modifiers, and package structure

  1. 4.1 Programming to interfaces
  2. 4.2 What are and how to use getters and setters?
  3. 4.3 The Builder Design Pattern
  4. 4.4 Organizing Packages in a Real Project
  5. 4.5 Encapsulation Patterns
  6. 4.6 Access Modifiers
  7. 4.7 Inner Class
  8. 4.8 The static keyword
  9. 4.9 Instance and static block
  10. 4.10 Small Real-World Project Challenge
  11. 4.11 Summary

5 Overloading

  1. 5.1 Overloading basics
  2. 5.2 Wrappers and autoboxing
  3. 5.3 Varargs
  4. 5.4 Overloading Real-World Usage Challenge
  5. 5.5 Summary

6 Inheritance and Polymorphism

  1. 6.1 When to use inheritance
  2. 6.2 Every Class is an Object
  3. 6.3 Checking the type of an object
  4. 6.4 The toString method
  5. 6.5 Access modifiers and inheritance
  6. 6.6 Object composition
  7. 6.7 Multiple inheritance in Java
  8. 6.8 Using super to access a parent class’s methods
  9. 6.9 Constructors and inheritance
  10. 6.10 Class casting
  11. 6.11 Preventing inheritance
  12. 6.12 Abstract classes
  13. 6.13 Factory Method Strategy Discount Real-world Challenge
  14. 6.14 Summary

7 Interfaces

  1. 7.1 Interfaces and Polymorphism
  2. 7.2 Covariant return types
  3. 7.3 Default methods
  4. 7.4 Abstract classes vs. interfaces
  5. 7.5 Static methods in interfaces
  6. 7.6 Simulating multiple inheritance with default methods
  7. 7.7 Private methods in interfaces
  8. 7.8 Command Design Pattern Challenge
  9. 7.9 Summary

8 Exceptions

  1. 8.1 Checked and unchecked exceptions
  2. 8.2 Stack Trace
  3. 8.3 Handling or Declaring Checked Exceptions
  4. 8.4 try, catch, finally
  5. 8.6 try with resources
  6. 8.7 Multi catch
  7. 8.8 Creating a customized exception
  8. 8.9 Throw early, catch late
  9. 8.10 Real World Exception Creation Challenge
  10. 8.11 Summary

9 Lambdas and Functional Interfaces

  1. 9.1 What is Lambda?
  2. 9.2 Functional Interfaces
  3. 9.3 Method Reference
  4. 9.4 Lambda Method Reference Matcher Challenge:
  5. 9.5 Summary

10 Optional

  1. 10.1 Wrapping a value into Optional
  2. 10.2 isPresent and isEmpty
  3. 10.3 Optional Antipatterns
  4. 10.4 ifPresent and ifPresentOrElse
  5. 10.6 Handling Exceptions with orElseThrow
  6. 10.7 Transforming Optional Data
  7. 10.8 Final Yoshi Food Optional Challenge
  8. 10.9 Summary

11 Generics and Object Comparison

  1. 11.1 Comparing objects with equals and hashcode
  2. 11.2 Generics
  3. 11.4 Upper and Lower Bound Generics
  4. 11.5 Summary

12 Collections

  1. 12.1 Collections API
  2. 12.2 List
  3. 12.3 ArrayList
  4. 12.4 Vector
  5. 12.5 Deque & Stack
  6. 12.6 ConcurrentModificationException
  7. 12.7 Using Comparable
  8. 12.8 Set
  9. 12.9 HashSet
  10. 12.10 LinkedHashSet
  11. 12.11 TreeSet
  12. 12.12 Map
  13. 12.16 TreeMap
  14. 12.17 Elements Searching
  15. 12.18 Summary

13 Streams

  1. 13.1 Streams Basic Principles
  2. 13.2 Creating a Stream
  3. 13.3 Intermediate VS Terminal Operation Methods
  4. 13.4 Intermediate Operations
  5. 13.5 Terminal Operations
  6. 13.6 Parallelizing Data Processing with parallel()
  7. 13.7 Collecting Data with collect()
  8. 13.8 Collectors.groupingBy
  9. 13.9 Summary

14 Newest Features of Java

  1. 14.1 Java Release Strategy
  2. 14.2 Introduction to Modules
  3. 14.3 Java JDK Base Modules
  4. 14.4 Named application module
  5. 14.5 Unnamed module
  6. 14.6 Exporting Packages from Module
  7. 14.7 Requiring a Module
  8. 14.8 Exporting a service with provides with
  9. 14.9 Module Reflection Access
  10. 14.10 Star Trek Planets Module Special Challenge
  11. 14.11 Reserved word var
  12. 14.12 New switch case statement
  13. 14.13 Using Pattern Matching Type Checks Java 15
  14. 14.14 Using record
  15. 14.15 Using Sealed classes Java 15
  16. 14.16 Text Blocks Java 15
  17. 14.17 Summary

15 Concurrency Fundamentals

  1. 15.1 Fundamentals of Concurrency
  2. 15.2 Thread
  3. 15.3 Using Thread sleep
  4. 15.4 Using join
  5. 15.5 non-daemon and daemon Thread
  6. 15.6 Using interrupt
  7. 15.7 Race Condition
  8. 15.8 Mutual Exclusion (Mutex)
  9. 15.9 Using wait and notify
  10. 15.10 Summary

16 Advanced Concurrency

  1. 16.1 ReentrantLock Basics
  2. 16.2 Atomic Variables
  3. 16.3 The volatile keyword
  4. 16.4 The happens-before Rule
  5. 16.5 CompletableFuture
  6. 16.6 Threadpool with Executors
  7. 16.7 ConcurrentHashMap
  8. 16.8 ConcurrentSkipListMap
  9. 16.9 Producer Consumer with BlockingQueue
  10. 16.10 Summary

17 Next Steps

  1. 17.1 Other important Java features
  2. 17.2 Practicing Clean Code
  3. 17.3 Tendencies of the market
  4. 17.4 Getting prepared for interviews
  5. 17.5 Strategies to Stay Sharp
  6. 17.6 Learn more about negotiation
  7. 17.7 Do you want more?

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