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 1 of 2
1
What are the key features introduced in Java 21?
easy
featuresjava21
2
Explain virtual threads in Java 21.
medium
virtual-threadsconcurrency
3
How do virtual threads differ from platform threads?
medium
threadscomparison
4
When should you prefer virtual threads over traditional threads?
medium
designperformance
5
Explain structured concurrency in Java 21.
hard
concurrencyarchitecture
6
What problem does structured concurrency solve?
hard
concurrencydesign
7
What are record patterns?
medium
patternsrecords
8
Explain pattern matching for switch in Java 21.
medium
switchpatterns
9
What are sequenced collections?
medium
collectionsapi
10
How do sequenced collections improve existing APIs?
medium
collectionsdesign
11
Explain the role of Scoped Values in Java 21.
hard
scoped-valuesconcurrency
12
How are Scoped Values different from ThreadLocal?
hard
comparisonconcurrency
13
What is unnamed patterns and variables?
medium
syntaxpatterns
14
Explain the Foreign Function & Memory API.
hard
ffinative
15
What are the benefits of Foreign Function API over JNI?
hard
jniperformance
16
Explain generational ZGC improvements in Java 21.
hard
gcperformance
17
What is string templates feature?
medium
stringssyntax
18
Why are string templates useful?
medium
securitystrings
19
Explain unnamed classes and instance main methods.
easy
syntaxbasics
20
How does Java 21 improve developer productivity?
easy
productivityfeatures
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