It is essential to know the similarities and differences between Scala vs. Java, whether learning a new programming language or implementing it in development. 

With plenty of languages being used and adopted in the big data ecosystem, it often makes an informed decision about choosing one language. Take Scala and Java, for example.

Both are among the top languages that are being used in the arena of programming. To know their differences, similarities, and key features, you need to read this article for comprehensive knowledge. Let’s start by going through the overview of these programming languages.

An Overview of Scala

Scala is a general-purpose language used for programming. It supports object-oriented and functional programming at the same time. This JVM-based language derives its influence from Java, Common Lisp, Haskell, Scheme, etc. 

Since Scala has been designed to address certain drawbacks in Java, it is packed with several advanced features you will not find in Java. This language not only runs on Java Virtual Machine but also supports existing Java programs.

Scala gets its name from two words — scalable and language. It wants to convey that this language is scalable and can expand per users’ needs. 2004 was the year when Scala got released publicly. 

Scala overview

Designed by Martin Odersky, this language did not take much time to become popular among the developer community due to its language interoperability and support for functional programming paradigms.

The use of Scala is commonly seen in domains like web apps, desktop applications, enterprise-level applications, and data analytics. Moreover, fields like distributed and concurrent programming also find this language highly beneficial.

Thanks to its compatibility with Functional Programming (FP) and Object-Oriented Programming (OOP), you will find Scala the absolute fit for real-time streaming processes and programs. Whether machine learning or casual desktop apps, this versatile programming language can build high-performing apps for all purposes.

Key Features of Scala

  • High-level and modern programming language.
  • Java Interoperability feature enables the use of libraries written in Java.
  • A statistically-typed language that consists of an advanced type interface system
  • Supports object-oriented and functional programming separately
  • It also supports a blend of both OO and FO paradigms.
  • This language is concise, expressive, and readable.
  • Comes with Built-in patterns and best practices
  • Contains a well-designed code structure
  • Less boilerplate compared to other languages.

An Overview of Java

Java is an immensely popular language that developers love to use. Some characteristics that define this language are general-purpose, high-level, object-oriented, and class-based. 

James Gosling of Sun Microsystems was the original developer of this language that can be run anywhere once written. Oracle acquired Sun Microsystems in 2010, and since then, it has owned the Java language.

The diverse capabilities of Java made it reach the top form in 2015. It has been steadily holding its position since then. Java is widely used in android app development, dynamic web apps, data centers, gaming consoles, and supercomputers.

Java overview

When it comes to popularity, no programming language can beat Java, except C and C++. You can see its presence in desktops, mobiles, games, large-scale industrial applications, scientific applications, IoT, and big data apps.

Since it has been in the market for more than two decades, numerous enterprises, manufacturers, banks, retailers, and financial companies have become dependent on Java. Moreover, it continues to inspire the development of many new programming languages.

All in all, Java is not just another programming language. You can also consider it a vast ecosystem involving many developers, a supportive community, and the big enterprises that use Java.

Key Features of Java

  • With Java, it is and easy-to-code and simple to use
  • An OOP language that has a modular approach
  • Boasts an extensive and enriched set of libraries and APIs
  • A platform-independent language that can run on various platforms using Java Runtime Environment
  • Secure and stable, which is scalable as well
  • It has an active community of developers and enthusiasts
  • The go-to programming language for almost everything – data science apps, ML apps, IoT, dynamic web apps, real-time data-centric apps

Scala Vs. Java: Differences

These languages are different from each other in various aspects. In the following section, we will shed light on some crucial parameters of differences.

Code Complexity 

As you write on Scala and Java, you will notice how verbose Java is compared to Scala. In Scala, you can write concise and compact code. On the other hand, Java needs you to write long-form codes, even for routine tasks.

Though Scala language might seem more complicated than Java, you can easily replace 20-lines of “easy and simple” Java code with one line of “complex” Scala language.

Type

As said earlier, Scala is a statically-typed language while Java is dynamically-typed. The major limitation of a dynamically typed language like Java is you need to test it for different scenarios to find out if the code is 100% devoid of bugs. Therefore, you might come across severe defects in Java code that do not appear before the production phase.

Structures

Developers can avail of features like automatic type inference and case classes while using Scala. Customization allows you to transform Scala into a domain-specific language (DSL). This feature is not available for Java.

Learning Curve

Needless to say that Java is easier to learn. The Scala learning curve is quite steep as it has a confusing syntax. Moreover, many learners find Scala to be complex and tricky because it involves less coding and hence, is difficult to predict.

Concurrency

Scala uses the actor model to simplify thread communication and control. Defining each object as an actor that has unique behavior, this language improves the process efficiency.

But, Java developers have to adhere to the traditional thread-based concurrency model. During code execution, it splits the program into multiple concurrently running tasks. 

Interoperability

Scala and Java are interoperable languages. While working on a Scala code, you can directly call Java functions inside it. Still, this process might be complicated for most developers as these languages implement interfaces and annotations differently. 

Tools and Frameworks

Scala is still in the emerging phase, but it does encourage developers to create new tools and frameworks for this language. ScalaTest, SBT, ScalaCheck, Gradle, and Scalaz are some popular Scala tools.

Since Java is a more mature language than Scala, it has a more enriched range of packages, tools, and IDEs to perform various development operations. Some of its popular tools are Apache Spark, Eclipse, Android Studio, Jenkins, and so on.

Community

Scala is an open-source project that boasts a diverse community working to improve the language. Scala Center maintains the language and takes care of the documentation.

Community

Due to the age and popularity of Java, it has a more mature and stable community than Scala. The wide community of Java developers comes from all over the world. You can always ask for assistance from the Java developer community.

Error Handling

As a developer, handling errors is way more flexible for you as you can opt for any of the multiple approaches. Java manages the errors successfully. Here, you will even find chain exceptions for particular failure types.

Performance

The performance of both languages depends mainly on the app size, features, and other parameters. Nevertheless, both are powerful and interoperate with each other without any difficulty. 

Scala has a shorter-looking code than Java and robust and expressive features that developers can utilize to build high-performant apps for different platforms.

Backward Compatibility

Backward Compatibility

Java language is backward compatible. If you write a code with the latest Java version, you can run it on a system containing an older Java version. On the other hand, Scala does not support backward compatibility.

Operator Overloading

Scala’s support for operator overloading is another feature that sets it apart from Java. This feature allows a programmer to overload any Java operator and, if needed, create new operators. On the flip side, Java doesn’t support this feature.

Lazy Evaluation

This is one built-in smart attribute of Scala language that makes it different from Java. This ‘lazy evaluation’ feature lets the developers postpone the time-consuming computation until it is necessary to perform. 

CriteriaScalaJava
Code ComplexityCompact and conciseVerbose codes are lengthy
TypeStatically-typed language Dynamically-typed language
Learning CurveThe steep learning curve more challenging to learn than JavaA flat learning curve can be understood easily
StructuresComes with a customizable structureAdditional features like case classes and automatic type inference are unavailable
ConcurrencyUses actor-modeltraditional thread-based concurrency model
InteroperabilitySupports interoperability with JavaSupports interoperability with Scala
Tools and FrameworkScalaTest, SBT, ScalaCheck, Gradle, and ScalazApache Spark, Eclipse, Android Studio, Jenkins
CommunityHas a growing communityHas a wide and stable community
Error HandlingOffers multiple methods to developersStrictly handles errors
PerformancePerfect for high-performance app developmentSuitable for all kinds of app development
Backward CompatibilityAvailable on ScalaUnavailable on Java
Operator OverloadingIt supports overloading operators and creating new onesIt does not support operator overloading
Lazy EvaluationIt comes built-in with ScalaNot available
Scala vs. Java: Differences at a glance

What Are the Similarities Between Scala and Java

There is no need to think that these two languages have only differences. Here are some features where you will find similarities between Scala and Java:

#1. Both Scala and Java are object-oriented languages. Both can be used to model the real world.

#2. Both these languages are multi-paradigm. These are concurrent and use statements to alter the state of a program.

#3. Scala and Java run Java Virtual Machine or JVM. The source code of Java and Scala compiles into Java-run byte code. 

# 4. When it comes to typing, both are statically-typed languages and also strongly-typed. It is pretty opposite of the Python language, which is dynamically typed. 

Learning Resources

Now that you have a fair idea about Scala vs. Java, you can take assistance from the following resource to learn one or both the languages:

Scala for Java Developers: A Practical Primer

This is an ideal book for Java developers keen to learn Scala without prior experience. With the help of this book, you can quickly grasp the Scala fundamentals and understand how it is different than Java.

It enables you to utilize your knowledge of Java to initiate your functional programming journey. Besides offering you a complete tour of Scala, it will also teach you the difference between Scala vs. Java and how you can adopt this language in an existing Java team. 

It will also help you get familiarized with the concepts and idioms of functional programming. After completing this book, you will have no trouble kick-starting your career with Scala.

Java Programming Masterclass: Udemy

Whether you want to become a Java programmer or earn valuable Java Certification, Java Programming Masterclass by Udemy is here. The course contains 401 lectures that help you build all the necessary skills to land your first Java programming job.

Java Programming Masterclass: Udemy

Highlighted features of this course are:

  • Full lifetime access to 80 hours of on-demand video and three articles.
  • Compatible with TV and smartphones.
  • Certificate from Udemy upon completion of this course.

Moreover, it will teach you the best practices of the Java software development industry. Besides the core Java skills, you will learn to perform the transition to Java EE, Spring Framework, and Android development. Before taking the Oracle Java Certificate exam, you can use it as a preparation course.

After completing this course, the participants can showcase their expertise in the latest version of Java to future employers and hiring managers. It increases their employability and puts them in a position to negotiate a competitive salary.

Concluding Thoughts

It is evident from the discussion that both Scala and Java have powerful features, though they are different in many ways. While Java is popular due to its flexibility, Scala is still in evolving phase that emphasizes stability.

Since the choice of language relies on individual requirements, you should make the right choice after going through this post.
If you are interested in some more programming language comparisons, check out the article on C vs. C++.