What Is Kotlin and What Is It Used For?



Kotlin is a free, open-source programming language. It was designed and developed by JetBrains under the Apache 2.0 license. It is an object-oriented programming language. It is designed first for Android and Java Virtual Machine. The first officially recognized programming language for Android application development is Kotlin. It is a simple, versatile and secure programming language. There are fewer lines of code required in Kotlin.

Kotlin is a functional language based on the Java Virtual Machine (JVM). As a result, it cuts down on many generic codes used in other programming languages. The syntax is very similar to that of Java. It is very simple for Java programmers to remember any Kotlin syntax. Any application can benefit from Kotlin’s improved performance and minimal runtime. Kotlin is mature to make it easier to create an interoperable application. The brand-new Kotlin programming language offers developers a fresh start. Despite being developed on the JVM, it is not a Java replacement.

Common Kotlin Concepts

Some common Kotlin concepts developers should be familiar with include:

  • Variables – Declared with val (read-only) or var (mutable). Type is inferred if not declared.
  • Functions – Kotlin functions can have default parameters, be inline, tail-recursive, single expression, etc.
  • Classes – Support inheritance, visibility modifiers, constructors, interfaces, and delegated properties.
  • Properties – Backed by getter/setter implicitly. Can be mutable, immutable, delegated etc.
  • Null safety – References are non-null by default. Use safe calls ‘?.’ and elvis ‘?:’ operators.
  • Lambdas – Anonymous functions used along with higher-order functions like map, filter, etc.
  • Coroutines – Lightweight thread-like entities to write asynchronous non-blocking code.
  • Data classes – Automatically generated equals(), hashCode(), toString() for data holder classes.
  • Type aliases – Give existing types new names for brevity or to denote meaning.
  • Extension functions – Allow adding new functionality to existing classes without modifying them.

Uses of Kotlin

Programming professionals use Kotlin. Kotlin can be used in platforms such as Java Virtual Machine, Android, Linux, macOS, iOS, Windows,  etc. Programming professionals mainly use Kotlin for the following. 

1. Back-End Web Development 

Kotlin is mainly used for back-end web development because they write less code than Java. Kotlin’s code is the same code as Java’s. The majority of Java’s vocabulary can be reduced in Kotlin. Kotlin code is typically shorter and more straightforward than Java code. Kotlin is especially useful for projects. By dividing this normal code toward the back-end development between various modules and levels of proficiency can soar. 

Kotlin targets the Java Virtual Machine, JavaScript, or native code and offers syntax and concepts similar to those of C++, Java, or Scala. Kotlin compiles down to Java bytecode, so for those back-end engineers with a JVM foundation, Kotlin will not be difficult to get a handle on.

2. Android Application Development 

Kotlin is the best programming language for Android application development because over 2.5 billion active Android users are in over 190 countries. The Integrated Development Environment (IDE) supports Kotlin. Therefore, programmers can easily utilize Kotlin’s code when developing Android.

Developers who use Kotlin to create Android apps can get prompt assistance from other community members. Kotlin is currently the undisputed choice for businesses seeking robust, scalable, and secure Android app development technology to support their business objectives.

3. Full-Stack Web Development 

With Kotlin, front-end code can be written in the same language as back-end code. To run in a browser, Kotlin compiles them both into JavaScript. Syntax, shared libraries, and programming paradigms can remain consistent across the front and back ends using Kotlin.

4. Server-Side Development 

Kotlin is excellent for server-side web development. kotlinx.html is a DSL for building HTML for Web applications. It is an alternative to FreeMarker and JSP. Kotlin’s support for Coroutines assists with building server-side applications. In addition to providing access to powerful web APIs and browsers, Kotlin ensures that you remain type-safe throughout.

5. Cross-Platform Mobile Development 

Kotlin’s multiplatform mobile permits using the abilities native to Android and iOS devices. The best feature of Kotlin’s multiplatform mobile is that creating a cross-platform application does not necessitate introducing new programming languages. This makes the mobile development process easier. It will enable Android and iOS users to have the experience they want.

Kotlin has an SDK to make cross-platform mobile application development easier. This SDK allows using the same code for Android and iOS apps.

Kotlin uses the following steps for cross-platform mobile development.

  • Install and select the Kotlin Multiplatform Mobile (KMM) plugin.
  • Develop project.
  • Select the project template.
  • Configure the KMM project.
  • Start coding.
  • Edit configuration and run the project on the stimulator.

6. Data Science 

Data scientists use scientific processes, algorithms, and systems to extract knowledge and insight. They frequently use Java in their field of work to accomplish this. Data scientists use the Kotlin alternative to Java because they can use all the standard Java libraries from previous projects while writing their code in Kotlin. They use Kotlin and libraries, such as kmath, kotlin-statistics, Krangl, kravis, and lets-plot.

For many data science topics, Kotlin can solve many problems. In Slack, the Kotlin community has a special channel called data science.

Getting Started with Kotlin

To start using Kotlin, you must set up your development environment. Here are the basic steps:

  1. Install the JDK: Kotlin compiles to JVM bytecode, so you will need a JDK installed. Oracle JDK 11 or OpenJDK are recommended.
  2. Install an IDE: IntelliJ IDEA, Android Studio, or VS Code with the Kotlin plugin are popular choices. These provide code completion, debugging, and other features.
  3. Create a project: In your IDE, choose “New Project” and select “Kotlin” as the language. You can create simple Java-based or Android apps to get started.
  4. Write some code: Here is a basic “Hello, World!” program:
fun main() {   println(“Hello, World!”)}
  1. Run the code: Click the run button or use a shortcut like CMD/CTRL + F10. The output will be displayed.
  2. Learn basic syntax: Through tutorials or books, familiarize yourself with variables, functions, control flow, classes, and objects.
  3. Expand your knowledge: Learn about more advanced topics like generics, coroutines, extensions, testing, syntax features like lambdas.
  4. Practice: Build small sample apps and libraries to gain experience applying Kotlin in real code.
  5. Refactor Java code: Start migrating existing Java codebases to Kotlin file by file to become comfortable with interoperability.
  6. Build real apps: Use Kotlin for developing Android apps, web backends, desktop programs, and more as your skills grow.


In  this article we discussed Kotlin and its uses. We hope that this article has given you a brief idea about Kotlin and now you can go on and learn more about it and get your hands dirty to code.