Kotlin vs Scala – Choosing the Right JVM Language 

Kotlin or Scala? A lot of businesses have this doubt at the time of choosing some of the most widely used Java virtual machine (JVM) languages. Both languages are quite similar and aim at enhancing Java.    

This makes Kotlin vs. Scala, one of the most frequently asked questions or queries on the internet.  

If you have the same doubt, then this blog is for you. In this blog, we will learn about Kotlin and Scala, their features, advantages/disadvantages as well as the differences between the two.   

We want confused businesses looking to build apps using JVM languages, to make the most suitable choices. Do you also want to choose the most relevant and lucrative option? If yes, then keep reading. Also you can develop an Android application with Kotlin. 

What is Kotlin?  

Kotlin is an object-oriented, open-source programming language that was released by JetBrains in 2011. Named after Kotlin island, near St. Petersberg in Russia, Kotlin was an attempt to cover the shortcomings of Scala as well as Java.   

However, this programming language maintains interoperability with Java. This allows developers to easily call Java codes from Kotlin and the other way around. The built-in null safety feature allows smooth development of the Android app without the NullPointerException (NPE).   

While it simplifies web and mobile app development, it places special focus on Android app development. In fact, in 2019, Google announced Kotlin to be the preferred language for the Android platform.    

Kotlin supports multi-platform programming which is one of its key benefits and advantages. Started with JVM as the primary target platform, the current version of Kotlin allows easy compilation of sources for other platforms, such as JS as well as native platforms.   

Being a lightweight language, Kotlin offers multiple advanced features such as serialization and concurrency through extension libraries. And since it is an easy-to-manage language, it allows developers to create a wide variety of server-side applications. It further maintains a cross-platform layer for native apps.   

Also read: Kotlin Vs Flutter

Some key Kotlin features are:   

• Offers compatibility with Java, Android as well as web libraries  
• More concise and expressive syntax than Java  
• Extension functions  
• Offers integration with different types of Java IDE  
• Supports higher-order functions  
• Extensive community and support  
• Ease of maintenance and code reading  
• Facilitates overloading operators  

Some advantages of Kotlin:   

• Backed by Google or JetBrains.  
• The code is short, contains fewer bugs, and is easier to read through boilerplate code; also offers high development speed.   
• Offers OOP features with a functional programming approach.   

• Offer high compatibility Java code.   

Some Kotlin disadvantages:   

• Does not offer complete support for pattern matching.   
• It offers limited use cases. Most ideal for Android mobile app development. Not as useful and relevant for other apps.  
• Has a smaller community to extend support; fewer tutorials, tools, and expert support.  

Some popular brands that use Kotlin are:  

Also read: Ultimate Guide To Migrate From Java To Kotlin 

What is Scala?  

Scala is another JVM language that was developed in 2001 and released publicly on the JVM platform in 2004, as a Java enhancement.  

It is a general-purpose, object-oriented computer language that offers multiple programming language features. Scala is more suitable for large-scale programs for functional programming.   

The source code compiles to Java bytecode, enabling execution on JVM. Developers can further code Scala in the similar way they do for Java and use multiple Java libraries. It possesses features such as code conciseness, higher-order functions, etc.   

It additionally includes several features that Java lacks, such as optional parameters, named parameters, operator overloading, and raw strings, inspired by other languages such as Scheme, Standard ML, and Haskell.  

Scala has an extensible as well as flexible code syntax. The language integrates the features of object-oriented as well as functional programming language and infers information automatically. It turns variables mutable or immutable at the time of declaring them.   

Some main Scala features are:   

• Offers immutability as well as concurrency control  
• Blends object-oriented and functional programming paradigms for syntax  
• Clear syntax with no boilerplate code  
• High-order functions  

• Facilitates quick errors and bug identification  
• Statically types and extensible language  
• Facilitates pattern matching and macros  
• Allows for overloading operators  

Some advantages of Scala:   

• Fully supports pattern matching.   
• Has been in the market for over 15 years and enjoys bigger and more extensive community support; has an abundance of resources, tutorials, and additional material.   
• Offers a highly flexible coding environment.    

Some Scala disadvantages are:   

• Interoperability with Java is not that great in the case of Scala. It introduces functional programming and classes and hence, there might arise some errors when calling from Java.   
• The compilation speed of Scala is slower than Java and Kotlin.   
• The null safety management within Scala has been called ineffective by a lot of developers. Scala substitutes null values with the option, which increases code complexity as it requires to be used explicitly.   

Popular global brands using Scala are:  

Kotlin vs Scala  

While Kotlin and Scala both have been attempts to better Java, they have certain similarities and some distinct features and functionalities, that make them suitable for different scenarios. Kotlin vs. Scala is a popular question, but there is certainly no clear winner in this tug-of-war.  

Both languages have witnessed rapid growth and popularity and are leveraged by contemporary behemoths for their app development purposes.   

Kotlin has 46.2k stars, 1.5k watchers, and 5.7k forks on GitHub. While Scala has 14.2k stars, 730 watchers, and 3.2k forks on the same platform.   

While both languages share fair levels of popularity, there are some differences that might make one better than the other for a specific case.  

Let’s look at these differences between the two JVM languages to understand their use cases and suitability better.   

Below is the tabular representation of Kotlin vs Scala, a comparison of Kotlin and Scala features, functionalities, and more. 

Factors/Parameters	Kotlin	Scala
Description	Kotlin is a hybrid language; it caters equally to both functional and object-oriented approaches.	Multi-paradigm programming language; can be used to write functions, however, holds each value as a discrete object, and thus, is more suitable for object-oriented programming (OOP) than for functional programming.
Type System (Refer to the image below this box for deeper understanding)	Statically typed language with a much easier type system than Scala.	Statically typed language; comes with one of the most sophisticated and comprehensive type systems.
Widely used Frameworks/Libraries	Spek, Klaxon, Kotlin NoSQL, Kanary, Kotlin-Core, etc.	Epic, Breeze, Saddle, Akka, Summing Bird, Smile, etc.
Ease of learning	Basic syntax as well as simple coding style; easy to learn language.	A powerful programming language with advanced features and a flexible syntax; difficult to learn.
Compilation Speed	Faster compilation speed in comparison to Scala.	Slow compilation; esp. for the complex enterprise-grade programs, takes a long time to compile compared to Java and Kotlin.
Ease of development/ coding	Simple syntax facilitates ease of coding and debugging.	Developers require time to understand the coding syntax.
Interoperability with Java	Offers complete interoperability with Java; Kotlin code could be called from Java and vice versa.	Offers limited interoperability with Java. Java classes are accessible however, Scala classes cannot be called in a Java environment.
Android compatibility	Ideal for Android app development.	Not commonly used for Android app development.
Code length	Short, clear, and compact code.	Usually larger and more expressive code.
Operator Overloading	Overloads basic operators but lacks flexibility.	Facilitates operator overloading bettering it for human-readable code.
Pattern Matching	Does not offer complete support for pattern matching.	Offers full support for pattern matching.
Null Point Exceptions	Null safety management is simpler and more effective.	Null safety management adds complexity to the code.
Inline Functionality	The compiler automatically considers functions with the ‘inline’ keyword as inline.	Developers need to request the compiler to inline a method by annotating it with @inline.
Ideal for	Android development, web development, as well as server-side development.	Big Data programming and ML solutions, projects with OOPS, and functional programming.
Community support	Small-sized community support.	Large and extensive community support.
Documentation	API documentation is extensive and lacks good organization.	API documentation is simple and well-organized.

 Kotlin type system; ‘Any’ represents the supertype of all non-nullable types whereas ‘Any?’ represents the supertype of all nullable types 

Scala has a unified type hierarchy; ‘Any’ is a supertype of all types with two direct subclasses, ‘AnyVal’, representing value types, and ‘AnyRef’, representing reference types. Additionally, there is Null, a subtype of all reference types, and Nothing, a subtype of all types. 

Next, we will look at the various use cases of these two programming languages.   

When should you use what?  

No matter how similar features and functionalities languages carry, they are always more suitable in some cases than in others.   

Use cases of languages or technologies help businesses choose the most relevant and suitable one for their project.   

So when should you use what? Let’s look.   

When should you use Kotlin?  

Below are the Kotlin use cases:  

• Since this language offers high interoperability, it is most ideal for projects combining Kotlin code and code written using Java.  
• Better for apps that have tighter performance requirements or that require frequent updates.   
• Suitable for novices or developers coming from other languages such as JavaScript, Ruby, etc; it reduces boilerplate code as well as offers a short learning curve.   

When should you go for Scala?   

Below are the use cases of Scala:  

• One of the most popular Scala use cases is big data programming. Its concurrency, pattern-matching features as well as great scalability make Scala suitable for apps that need to process massive amounts of data.  
• Businesses that are on a time crunch and looking for better speed should opt for Scala. It allows developers to write clear codes with fewer bugs.   
• Lastly, it is an ideal language for developing complex, multi-threaded systems.  

Conclusion  

While both languages are popular among developers and most effective in specific cases, it largely depends on the business and its project requirements.  With Android app development frameworks, you can create faster android apps quickly. So, stay tuned with us to find the best application frameworks in Android.  

Kotlin is an ideal option for Android development. However, beyond that, there are other, perhaps better options available. But Kotlin is a newer language and is still in its nascent stage. As a result, it is supported by fewer IDEs and comes with fewer libraries and frameworks than Scala.   

But at the same time, there is considerable room for improvements and upgradations for this young language. Some of its major shortcomings i.e., limited IDE support could be covered with constant work.   

Scala, on the other hand, is an older player but more suitable for large, complex projects. It is an ideal language for apps that are required to perform a lot of pattern matching or apps that require combinations of functional and OOP-style programming. The scope for improvement for this language, however, is limited in comparison to Scala.  

Thus, it majorly depends on the app that the business is planning to develop and the expertise/ resources it has at its disposal. Both the JVM languages perform well in their most suitable environments. So, the business must make a choice as per its project requirements.