What is Kotlin?
Kotlin is an industrial-strength, modern programming language developed by JetBrains. It is very concise, pragmatic and easy to learn. While the syntax is not compatible with Java, Kotlin is designed to be interoperable with Java, which means Kotlin works great with all existing Java code and libraries.
Despite the fact that Kotlin is a quite new programming language, it is already widely used in practice (especially in mobile and server-side development), and its popularity is constantly growing among developers around the world. Also, Kotlin has excellent documentation and official tutorials that will help you find answers to any questions that may arise.
Many developers who use Kotlin highlight that it makes development faster and more fun :)
Knowledge of Kotlin allows developers to write Android and server-side applications, useful frameworks, and libraries. As a general-purpose language, Kotlin can be used in many spheres such as the financial service industry, telecommunications, embedded systems, medicine, development tools (like IntelliJ IDEA), and so on. Developers can use Kotlin together with Java, or as the only language in their projects.
In addition to Java, Kotlin can also be compiled to JavaScript, which enables you to develop client-side web applications and run them in a browser — but that’s beyond the scope of this course.
Short history
In July 2011, JetBrains unveiled the Kotlin Project, a new language for the Java Platform, which had been under development for a year. The name comes from Kotlin Island, near St. Petersburg, Russia. The primary goal of this project was to provide a safer and more concise alternative to Java in all the contexts where Java is currently used.
In 2016, the first official stable version was released (Kotlin v1.0). The developer community was already interested in using this language, especially on Android.
At the Google I/O 2017 conference, Google announced first-class support for Kotlin on Android. You can read more about it here.
At present, Kotlin has several releases a year. The latest version can be found here.
Important features
Kotlin is designed as a pragmatic language, meant to solve real-world problems rather than for research purposes. It has a clear syntax that is similar to Java (but not the same). Kotlin reduces the amount of boilerplate, making your code easily readable.
As you already know, Kotlin has interoperability with Java, so it is possible to use all your existing Java libraries in Kotlin projects. It also allows companies to make a gradual migration from Java to Kotlin. Moreover, it is possible to call Kotlin code from Java as well.
It is also important that Kotlin supports multiple programming paradigms, such as imperative programming, object-oriented programming, generic programming, functional programming, and more. You will learn these paradigms throughout the course.
Last but not least, Kotlin is a tool-friendly language, which means all popular development tools such as IntelliJ IDEA, Eclipse, and Android Studio support it.
The sample of Kotlin program
Here is a sample of a simple Kotlin program that prints Hello, Kotlin!. You may start it by clicking on the green triangle.
fun main(args: Array<String>) {
println("Hello, Kotlin!")
}Now, you do not need to understand how this code works, just enjoy it! :)