Java 13 Interview Questions and Answers (2024)

1. Q: When Java 13 was released?
2. Q: What are features of Java 13?
3. Q: What is AppCDS?
4. Q: What Dynamic CDS Archives?
5. Q: What was enhanced for Z Garbage Collector (ZGC) in Java 13.?
6. Q: What has been improved in Reimplement the Legacy Socket API feature in Java 13?

Q: When Java 13 was released?
Ans:

Java 13 is the open-source reference implementation of version 13 of the Java SE Platform. JDK 13 reached General Availability on 17 September 2019

Q: What are features of Java 13?
Ans:

The aim of the LTS version is to complete the preview capabilities so that they are stable enough and look good for the next three years.

1. Dynamic CDS Archives
2. ZGC: Uncommit Unused Memory
3. Reimplement the Legacy Socket API
4. Switch Expressions (Preview)
5. Text Blocks (Preview)

Q: What is AppCDS?
Ans:

The concept behind AppCDS is to create and share a class data archive once, so that the JVM does not need to recreate it. AppCDS greatly reduces the amount of time JVM spends on loading classes.

Q: What Dynamic CDS Archives?
Ans:

Commercial class-data sharing (CDS) feature was there since Java 8, however it gets evolved over several Java releases (10,12,13). Java 13 extended the feature to allow the dynamic archiving of classes at the end of Java application execution.

Q: What was enhanced for Z Garbage Collector (ZGC) in Java 13?
Ans:

Java 11 has introduced Z Garbage Collector (ZGC), which had short pause while cleaning up the heap memories and it was not returning unused memory to operating system even though memory was unused for long time. Now Java 13 has extended the feature to return unused heap memory to the operating system.

Q: What has been improved in Reimplement the Legacy Socket API feature in Java 13?
Ans:

Java 13 introduces a new NioSocketImpl class as a replacement for PlainSocketImpl, which make simpler and more modern implementation that is easy to maintain and debug.