Kotlin Tutorial

These days, many developers prefer Kotlin over Java for Android development. One of the reasons for this is Google’s announcement in 2019. In that announcement, Google declared Kotlin as its preferred language for android app development and endorsed complete support for it. Another reason is based on the fact that Kotlin is more concise and also interoperable with Java. Now, Kotlin is being perceived as an alternative to Java. 

In This Kotlin Tutorial, You Will Learn

What is Kotlin? Kotlin History Kotlin’s Features Kotlin vs Java Kotlin vs Scala

What is Kotlin?

Developed by Jetbrains, Kotlin is a statistically typed programming language intended for Java Virtual Machine (JVM), Android, JavaScript, and Nativ. It is also a free and open-source language having both object-oriented and functional constructs. Since Kotlin supports function types, higher- functions along with lambdas, it is considered the best choice for programming. The major focus of Kotlin is on safety, interoperability, and support for tools.

Kotlin History

The history of Kotlin dates back to 2011 when Jetbrains, a company headquartered in Prague, Czech Republic, developed a unique language for JVM. Kotlin, which got its name from Kotlin Island, near St. Petersburg, became open source in 2012. The first official version of Kotlin came in 2016 and got support for Android in 2017 by Google. In Kotlin 1.2 release, the sharing of code between JVM and JavaScript platforms feature was added and in Kotlin 1.3 release, Coroutines for asynchronous programming have been included. In the year 2019, Google endorsed its complete support to Kotlin announcing it as their preferred language for Android development.

Why do programmers prefer Kotlin?

The major advantage of Kotlin is you can use it for any kind of development - be it server-side, client-side web, and Android. You also can use it for mobile and server-side applications, client-side with JavaScript or JavaFX, and data science, etc. On the operation systems front, you can use Kotlin in iOS, macOS and embedded systems, etc.

Some of the other advantages of Kotlin include:

• You don’t need to write much code in Kotlin. Due to this, the bug count will be less.
• The bug count will be less even due to Kotlin’s support for a test-driven environment.
• Even the maintenance is less because of less code and fewer bugs.
• Kotlin makes life easier for you because it supports multiple plugins.
• Using Kotlin, it is easier to debug in writing applications.
• Kotlin can run on any operating system.
• Kotlin is compiler efficient.
• Kotlin has a standard and modern library.
• In Kotlin, the semicolons are exceptional.
• You can easily understand the code in Kotlin.

Kotlin’s All-round Development Abilities

Kotlin can be said as an all-rounder language since it provides support to multiple kinds of development. Here is an insight into Kotlin’s all-around development capabilities.

• Support to Android: This is the major feature of Kotlin. Kotlin provides excellent support to Android and you can see multiple applications have already been developed using Kotlin. Some of these applications include Pinterest, Coursera, Trello, Evernote, Basecamp 3, Simple Calendar, and KotlinConf, etc.
• Support to Desktop Development: Kotlin also supports desktop development. To achieve this, you can use Java UI Frameworks such as JavaFX or Swing. You also can use TornadoFX, which is a Kotlin specific framework.
• Support for Web Development:  Another development ability of Kotlin is its support for web development. You can use Kotlin/JS for this purpose.
• Support to Server-side Development:  Since Kotlin is cent percent compatible with JVM (Java Virtual Machine), it provides excellent support to server-side development. You can use frameworks such as Spring Boot, Vert.x, Ktor, Micronaut, Javalin, and JSF, etc. for server-side development. The advantage of using Kotlin in server-side development is - it provides writing expressive and concise code along with interoperability.

Kotlin’s Features

Some of the major features of Kotlin are the following:

• Easier maintenance: Being a modern language, Kotlin provides you to write less boilerplate code and also allows you to express your ideas. This makes it maintenance easier as there will be less testing due to less code. 
• Interoperability with the Java programming language:  Kotlin is 100% interoperable with the Java programming language. So, you can either call Kotlin from Java-based code or Java-based code from Kotlin.
• Improved quality: With Kotlin, you can improve the quality of the applications. You can avoid common programming mistakes using Kotlin’s multiple language features.

Kotlin vs. Java

Both Kotlin and Java are powerful languages with rich features. Java, being one of the oldest object-oriented programming languages, has an excellent feature in the form of concurrence, which allows the execution of multiple statements. Besides, Java is an independent programming language, which provides – write once, run anywhere. On the other hand, Kotlin is a modern-day’s language, which has advantages including conciseness, interoperability, less error-prone, and less learning curve, etc.

If we look at the differences between these two, Kotlin has a slight edge over Java having features such as null safety and lambda expressions whereas Java doesn’t support these. On the other hand, Java is better than Kotlin in terms of compilation speed and code development speed. Besides, the community circle of Java is bigger than Kotlin. Though Kotlin looks more concise and also more streamlined, when compared to Java, both have their advantages and disadvantages. What is needed to be understood here is - they cannot replace each other but they exist on their own. However, they can be used hand-in-hand in Android development. 

Explore - Kotlin vs Java

Kotlin vs. Scala

Scala is a high-level language, which is a combination of object-oriented and functional programming. Scala can run on Java Virtual Machine and also can interoperate with existing Java code and libraries. Using Scala, you can avoid bugs in complex applications. Besides, you can develop high-performance systems using JVM and JavaScript runtimes.

Does it mean Scala is better than Kotlin?  Or Kotlin has an edge over Scala? Or both are equally capable? Now, let us see the differences between Kotlin and Scala.

Here is a comparative insight.

Pros.

Kotlin	Scala
Most preferred language in the Android community	Doesn’t have much support from Android
Ranked 11th among the best programming languages to learn first	Ranked 17th among the best programming languages to learn first
Expressible, concise, and efficient code	Supports Macros, Pattern Matching, and Higher-Kindred Types
Provides functional and object-oriented paradigm features	Operator overloading
Succeed Java efficiently because the codes of Kotlin and Java are inter-convertible	Large community support
Looks similar to Java and endures object-oriented features
Works well with Java programming tools including Maven, Eclipse, and Gradle, etc.

Cons.

Kotlin	Scala
No support to pattern matching	Lacks speed in the compilation
Absence of raw types	Lacks efficiency in null safety management
Absence of invariant arrays	Challenge in the binary compilation
Absence of SAM Conversions	-

From the above comparison table, we can conclude that Kotlin is a better programming language than Scala.

Kotlin’s interoperability with Java and JavaScript

Kotlin is interoperable with both Java and JavaScript. It has two compilers - one generates bytecode, which can be executed in the Java Virtual Machine and another one produces only JavaScript.

Let us first see Kotlin’s interoperability with Java

Since Kotlin is designed and developed to be interoperable with Java, you can call the existing Java code from Kotlin in a natural manner. Similarly, you can use Kotlin code from Java smoothly. In the Kotlin programming language, Java declaration types are treated specially and called platform types. These platform types are safe because null checks are relaxed for them. Kotlin treats getters and setters as properties using the same name in case they exist in a Java class. Similarly, Boolean accessor methods are treated as properties in Kotlin.

Let us now see Kotlin’s interoperability with JavaScript

Similar to how you can call Java from Kotlin and vice versa, you can even call JavaScript from Kotlin and vice versa. This is because Kotlin runs together with the Javascript source in the same JavaScript engine when the Kotlin compiler is used.  Using dynamic types or strongly typed Kotlin headers for JavaScript libraries, you can interact freely with JavaScript from Kotlin. However, if you wish to have Kotlin’s type system completely, then you need Kotlin’s headers for JavaScript libraries.

When it comes to calling Kotlin from JavaScript, it would be easier because you can freely use the JavaScript classes, functions, and properties generated by the Kotlin compiler.

Kotlin Coroutines

Coroutines are lightweight threads, which help in improving application performance. In an Android-based app, they help in managing long-running tasks and providing safety.  Using the Coroutines, you can write asynchronous code, which is readable and maintainable perfectly. When compared with default Java threads, the Coroutines in Kotlin Programming language consumes less memory and time as well. Coroutines also make computation easier without blocking the other threads.

Benefits of using Kotlin in Android Development

As discussed earlier in this article, Android has complete support for Kotlin. It has been announced by Google in 2019 that Kotlin is its preferred language for Android development. Several applications have already been developed using Kotlin and Android combinations.

Here are some of the benefits, which can be achieved using the potential combination of Kotlin and Android.

• Using Kotlin in Android development, you don’t need to spend much time in code writing.
• It is easier to integrate Kotlin with Android.
• Since Kotlin is interoperable with Java, you can use both of them together in your applications. You don’t need to migrate the code into Kotlin.
• Using Kotlin, you can avail of the advantage of sharing the common code across different platforms. This is because you can use Kotlin with IOS, web applications, and backend.
• With Kotlin, you can enjoy the benefit of code safety. Due to less code and enhanced readability, the errors also will be a few only. These errors will be detected by the Kotlin compiler and make the code safer.
• The learning curve is less in Kotlin. If you are a Java developer, it would be easier for you to learn Kotlin.
• Kotlin has large community support.

To sum it up

Kotlin is the most preferred language by the android developers because of its cent percent interoperability with Java, its all-around development capabilities, and multiple other benefits. Besides, Kotlin is also interoperable with JavaScript and is considered a better option than Scala.

Now let us see the career scope in Kotlin.

Career Scope in Kotlin

Since Kotlin is the preferred language for android, many companies are moving towards Kotlin overlooking Java. In just eight months the usage of Kotlin has doubled jumping from 7% to 14%. This phenomenal increase is attributed to Google’s announcement of making Kotlin its preferred language. Besides, there are indications that most of Google’s projects will be done in Kotlin as it increases its investments in Kotlin. Major organizations such as Amazon Web Services, Pinterest, Coursera, Prezi, Basecamp, Netflix, and Uber, etc. have already adopted Kotlin. Given all these positives, you can expect an excellent scope in Kotlin.  

Joining the Kotlin course at Mindmajix will certainly enable you to learn all the nuances of Kotlin and makes you an expert in building Android applications. Once the course is completed, you will be eligible for the Kotlin certification, which provides you with an edge in the job market.