Top Features of Java 21

37mIntermediate2025-09-04

Authors

Bethan Palmer

Developer

Course details

In this course, developer Bethan Palmer guides you through the top features of Java 21. After an overview of the Java release cycle, dive into string templates, sequenced collections, and record patterns. Learn about pattern matching with switch statements, as well as how to use unnamed patterns and variables. Discover the new way to define main methods and find out what an unnamed class is. Plus, explore virtual threads and generational ZGC.

Learning objectives
Recall the most common features of Java 21
Summarize what each feature is
Demonstrate how to use the features

Skills covered

JavaOracleProgramming LanguagesSoftware DevelopmentOne-Off

Concepts

Introduction

Learn Java 21's top features

Java Release Cycle

Understand the Java release cycle

String Templates

Using String templates

Sequenced Collections

Using sequenced collections

Record Patterns

Using record patterns

Pattern Matching for Switch Statements

Using pattern matching for switch

Unnamed Patterns and Variables

Using unnamed patterns
Using unnamed variables

Unnamed Classes and Instance main Methods

Using unnamed classes and instance main methods

Virtual Threads

What are virtual threads
Using virtual threads

Generational ZGC

What is Generational ZGC
How does Generational ZGC work

Conclusion

Next steps