Both Java and Scala are object-oriented programming languages running on Java Virtual Machine (JVM). But Java is a mature and dynamic programming language, whereas Scala is a modern-age programming language. According to many surveys, Java is the most popular programming language of 2015. According to the latest server side languages usage and market share trends on W3Techs.com, 3% of all websites are currently using Java, whereas Scala finds use in less than 0.1% of websites. So Java has a lot of importance in today’s developer community. But many studies have highlighted that the popularity of Scala is increasing consistently among modern developers. So the developers must understand the major differences between Java vs Scala to choose the better programming language for their project.
Java vs Scala: Important Points of Distinction between Java and Scala
Size and Quality of Code:
While using Java, developers generally have to write longer lines of code to accomplish common tasks. But Scala enables programmers to accomplish the tasks without writing longer lines of code. Further, it helps programmers to make the code more organized, readable and reusable. So many programmers opt for Scala to develop a concise, readable and maintainable code base.
Complexity of Code:
Despite helping programmers to accomplish tasks with less code, Scala has a more complex structure than Java. It requires developers to write a lower number of single line but complex code. On the other hand, Java enables developers to write longer lines of simple code. So many beginners find it easier to learn Java than Scala.
Java was introduced in 1995. So it was designed like other conventional programming languages. But it was subsequently upgraded with functional programming capability. The programmers can use Java 8 to write functional programs efficiently. But Scala was designed from the beginning as a functional programming language. Unlike Java, it has much better and advanced functional programming features like monads, immutability and concurrency.
Scala borrows most syntax and language features from Java. But it still has a number of structures that are not available in Java. For instance, Scala supports case classes and automatic type inference. The highly structured nature of Scala further enables programmers to convert it into domain specific language (DSL). Thus, the programmers have option to customize Scala’s look and feel according to the specific needs of their projects.
In theory, Java and Scala are interoperable with each other. So the programmers can call Java functions directly inside Scala code. But the developers may find it complicated Scala functions in Java code or Java functions in Scala code as each programming language has different features. Each language further implements interfaces, collections, annotations and other features differently. The complication often makes programmers write Java and Scala code separately.
While using Java 8, programmers should use the conventional thread-based concurrency model. The conventional technique divides the program into several concurrently running tasks at the time of execution. But Scala uses the actor model which is both modern and more efficient. It allows programmers to define each object as an actor with its own behaviour and mailbox. So Scala simplifies the thread communication and control, along with making the entire process more efficient.
According to many websites, Scala is faster than Java. Some programmers even claim that Scala is 20% faster than Java. Both these programming languages run on JVM. So pro code compiles into bytecode before running on JVM. But Scala compiler supports an optimization technique called tail call recursion. The optimization makes the Scala code compile faster than Java code.
Availability of Tools and Frameworks:
As noted earlier, Java is older and more mature than Scala. So obviously it allows programmers to take advantage of a wider range of IDEs, editors, frameworks and tools. However, the growing popularity of Scala encourages many programmers and enterprises to launch new tools and frameworks. Also, the Scala developers have option to use several Java development libraries and frameworks as it is also a JVM language.
On the whole, both Java and Scala find extensive use for building a wide variety of applications. But each programming language has its own strengths and weaknesses. So it is important for programmers to keep in mind the specific needs of their project, while comparing the two programming languages.