Book Image

Introduction to JVM Languages

By : van der Leun
Book Image

Introduction to JVM Languages

By: van der Leun

Overview of this book

Anyone who knows software development knows about the Java Virtual Machine. The Java Virtual Machine is responsible for interpreting Java byte code and translating it into actions. In the beginning, Java was the only programming language used for the JVM. But increasing complexity of the language and the remarkable performance of the JVM created an opening for a new generation of programming languages. If you want to build a strong foundation with the Java Virtual Machine and get started with popular modern programming languages, then this book is for you. The book will begin with a general introduction of the JVM and its features, which are common to the JVM languages, helping you get abreast with its concepts. It will then dive into explaining languages such as Java, Scala, Clojure, Kotlin, and Groovy and will show how to work with each language, their features, use cases, and pros and cons. By writing example projects in those languages and focusing on each language’s strong points, it will help you find the programming language that is most appropriate for your particular needs. By the end of the book, you will have written multiple programs that run on the Java Virtual Machine and know about the differences between the various languages.
Table of Contents (15 chapters)

Summary


In this chapter, we looked at the Clojure language, a language that is quite different from the other languages covered in this book. After writing a lot of one-line expressions in the REPL environment, I hope you discovered that learning the Clojure syntax is not that difficult at all. By just creating lists that contain expressions, often nested in multiple lists, one can write surprisingly readable code. We also learned that Clojure is a functional programming language and that its most important data structures are immutable. Unlike Java, Clojure is not an object-orientated language at heart, but it offers very good compatibility with the JVM platform. We created some instances of JVM objects and called methods and read fields from them. Finally, we looked at agents, a safe way to manage states in a multithreading application. We even wrote a simple application to try them out.

Now that you know the most important rules of Clojure, you are ready to write a real application.