Introduction to Scala: Scala vs Java

Java and Scala are hot languages for enterprise development. While Java is a reliable object-oriented language that's been around for years, Scala is a newer language used for improved scalability and functional programming. In this article, we discuss the key differences between Java and Scala. We'll examine each language independently and then compare performance between Scala and Java as well as the advantages of using Scala over Java for your application.

What is Java?

Java is a popular object-oriented language for building virtually any type of computer program. Java has been popularized for it's ease of use, reliability, and portability. Since Java runs on the JVM (Java Virtual Machine), it is platform independent. This means Java can run on any machine that supports the JVM. Through a continued emphasis on performance, simplicity, and security, Java has successfully evolved over time to support things like parallel operations, lambdas, etc. With the more recent releases of Java 9 and 10, the language even supports it's own JavaScript engine (Nashorn) as well as improved APIs for things like Date/Time to keep it competitive with platforms like Node.js.

What is Scala?

Scala is a general purpose language that emphasizes functional programming. For more on functional programming, check out What is Functional Programming?. Scala is similar to Java in that it compiles down to Java byte code and runs on the JVM. In fact, Scala is interoperable with Java. This means you can use Java and Scala interchangeably and that Scala is backwards compatible with Java code.

What's the difference between Scala and Java?

The main difference between Scala and Java is Scala's functional approach. Through an emphasis on immutability, Scala effectively bridges the gap between object oriented and functional programming languages. Things like type inference, lazy evaluation, pattern matching, and higher order types are key characteristics of Scala that separate it from traditional Java.

What is Scala used for?

Scala is most popular for large scale enterprise applications that benefit from a functional programming approach. This includes things like concurrent programming, distributed applications, web apps, utilities, data streaming, parallel batch processing, and big data analysis with libraries like Spark.

Scala vs Java Performance

It’s a common mistake to compare the performance of Scala and Java. This is because Scala is ultimately Java at the end of the day. Remember that Scala and Java both compile down to Java byte code and run on the JVM. You can find numerous benchmarks online that illustrate the performance consistencies between Java and Scala. Despite this similarity, it can be argued that Scala results in higher performance due to the nature of the Scala programming language. Through its functional approach, Scala enforces a more concise programming style that scales better with larger applications.

Advantages of Scala over Java

The main advantages of Scala include simpler and more expressive code. Functional programming means more independent units of code that don't disrupt or rely on shared state. Scala is also less verbose than Java. You can avoid a lot of boilerplate code when using Scala over Java. Also remember that Scala's interoperability with Java means you have nothing to lose by using Scala. You can still use traditional Java with a Scala application.


Scala and Java share many similarities. They both run on the JVM and ultimately compile to Java byte code. Scala adds some extra advantages over Java, including a less verbose, more concise syntax. Scala allows you to leverage the traditional advantages of Java (portability, security, performance) with a more functional approach to writing code. This makes Scala the ideal choice for larger applications emphasizing scalability.

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