Java 21 Interview Questions - Practice Latest Features & Concepts
Prepare for Java 21 interviews with real-world questions. Master new language features, concurrency enhancements, and modern Java practices with clear answers.
Top Java 21 Interview Questions for Freshers and Experienced
45 Questions
2 Pages
Easy · Medium · Hard
Page 2 of 2
1
What happens if a virtual thread blocks?
hard
virtual-threadsinternals
2
Can virtual threads replace thread pools?
medium
designthreads
3
How do you create a virtual thread?
easy
threadsapi
4
What is pinning in virtual threads?
hard
threadsperformance
5
Explain carrier threads in virtual threading.
hard
threadsinternals
6
What is the impact of virtual threads on scalability?
medium
performancethreads
7
How does Java 21 enhance switch expressions?
medium
switchlanguage
8
Explain guard clauses in switch patterns.
hard
patternsswitch
9
What are sealed classes and how are they used in Java 21?
medium
sealeddesign
10
How does Java 21 improve error handling in concurrent code?
hard
concurrencydebugging
11
What are the risks of using virtual threads incorrectly?
hard
threadspitfalls
12
How does Java 21 improve memory management?
medium
gcperformance
13
Explain use case of sequenced map.
medium
collectionsmap
14
What is a practical use of record patterns?
medium
patternsdesign
15
How does Java 21 support modern application design?
medium
architecturemodern
16
Explain debugging challenges with virtual threads.
hard
debuggingthreads
17
What is the role of preview features in Java 21?
easy
previewfeatures
18
How do you enable preview features?
easy
previewsetup
19
Explain impact of Java 21 on microservices.
medium
microservicesperformance
20
What are best practices when adopting Java 21?
medium
best-practicesmigration
21
How does Java 21 improve API consistency?
medium
apidesign
22
What are limitations of structured concurrency?
hard
concurrencylimitations
23
How does Java 21 enhance code readability?
medium
readabilitysyntax
24
What is a real-world scenario for virtual threads?
medium
use-casethreads
25
Compare Java 21 with previous LTS versions.
medium
comparisonlts
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