Orcacle releases new Java versions quite often and the current one is 19. However, plenty of production code is still running on older Java versions as even Java 8 is still supported. That's why in case you plan to move from Java 11 LTS (Long term support) to the new LTS - Java 19, here is what you should know.

There are some of the key differences and new features in Java 17 compared to Java 11:

  1. Sealed classes: This is a new language feature introduced in Java 17 that allows developers to restrict the types that can extend a class or implement an interface. This feature is not available in Java 11.

  2. Pattern matching for instanceof: This feature was introduced in Java 14 and has been improved in subsequent releases, including Java 17. It allows developers to use pattern matching with instanceof, making it easier to write type-safe code. This feature is not available in Java 11.

  3. Switch expressions: This feature was introduced in Java 12 and has been improved in subsequent releases, including Java 17. It allows developers to use switch as an expression, making it easier to write concise code. This feature is not available in Java 11.

  4. Records: This is a new language feature introduced in Java 14 that allows developers to create classes that are simple data containers with a compact syntax. This feature is not available in Java 11.

  5. Foreign Function and Memory Access: This is a new feature introduced in Java 14 that allows Java programs to call native code in a more efficient way. This feature is available in both Java 11 and Java 17.

  6. Vector API: This is a new API introduced in Java 16 that allows developers to perform vector computations, making it easier to write high-performance code. This feature is not available in Java 11.

  7. Enhanced switch statements: This is a feature introduced in Java 12 that allows developers to use switch statements with new capabilities such as switch expressions, arrow case labels, and yield statements. This feature is available in both Java 11 and Java 17.

  8. Application class-data sharing (CDS): This is a feature introduced in Java 10 that allows developers to improve the startup time and memory footprint of Java applications by sharing class metadata between different Java processes. This feature is available in both Java 11 and Java 17.

It's worth noting that Java 11 is a long-term support (LTS) release, which means that it will be supported with security updates and bug fixes for a longer period of time compared to non-LTS releases such as Java 17. However, Java 17 includes several new features and improvements that are not available in Java 11, so it may be worth considering upgrading to take advantage of these features.