Search icon CANCEL
Subscription
0
Cart icon
Your Cart (0 item)
Close icon
You have no products in your basket yet
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
Java Coding Problems

You're reading from   Java Coding Problems Become an expert Java programmer by solving over 250 brand-new, modern, real-world problems

Arrow left icon
Product type Paperback
Published in Mar 2024
Publisher Packt
ISBN-13 9781837633944
Length 798 pages
Edition 2nd Edition
Languages
Arrow right icon
Author (1):
Arrow left icon
Anghel Leonard Anghel Leonard
Author Profile Icon Anghel Leonard
Anghel Leonard
Arrow right icon
View More author details
Toc

Table of Contents (16) Chapters Close

Preface 1. Text Blocks, Locales, Numbers, and Math 2. Objects, Immutability, Switch Expressions, and Pattern Matching FREE CHAPTER 3. Working with Date and Time 4. Records and Record Patterns 5. Arrays, Collections, and Data Structures 6. Java I/O: Context-Specific Deserialization Filters 7. Foreign (Function) Memory API 8. Sealed and Hidden Classes 9. Functional Style Programming – Extending APIs 10. Concurrency – Virtual Threads and Structured Concurrency 11. Concurrency ‒ Virtual Threads and Structured Concurrency: Diving Deeper 12. Garbage Collectors and Dynamic CDS Archives 13. Socket API and Simple Web Server 14. Other Books You May Enjoy
15. Index

101. Handling nulls in nested record patterns

From Chapter 2, Problem 54, Tackling the case null clause in switch, we know that starting with JDK 17 (JEP 406), we can treat a null case in switch as any other common case:

case null -> throw new IllegalArgumentException(...);

Moreover, from Problem 67, we know that, when type patterns are involved as well, a total pattern matches everything unconditionally including null values (known as an unconditional pattern). Solving this issue can be done by explicitly adding a null case (as in the previous snippet of code) or relying on JDK 19+. Starting with JDK 19, the unconditional pattern still matches null values only it will not allow the execution of that branch. The switch expressions will throw a NullPointerException without even looking at the patterns.

This statement partially works for record patterns as well. For instance, let’s consider the following records:

public interface Fruit {}
public record SeedRecord...
lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at $19.99/month. Cancel anytime
Banner background image