Nepedia
Back to Discover
Advanced Reader
💻

Kotlin

technology Maturity 11-13 war conflict Next article →

This article covers sensitive topics: war_conflict. Parents can manage visibility in Parental Controls.

Kotlin is a high-level, general-purpose programming language designed for modern software development.

Kotlin logo (2025)
Kotlin logo (2025)

It is a statically typed language, meaning the type of data used in code is known at compile time. One of its most useful features is type inference. This allows the compiler to deduce the data type automatically, which creates a more concise syntax. Kotlin is built to be fully interoperable with Java. This means developers can use both languages together in the same project. This interoperability allows companies to migrate their existing Java codebases to Kotlin gradually.

Kotlin functions through several different compilation targets to reach various devices. Most commonly, it targets the Java Virtual Machine (JVM). When it runs on the JVM, it uses the Java Class Library. The Android Kotlin compiler produces Java 8 bytecode by default. However, it can also target newer versions, ranging from Java 9 up to Java 24. This allows for advanced optimization and extra features.

Kotlin logo light-on-dark
Kotlin logo light-on-dark

Beyond the JVM, Kotlin can compile to JavaScript. This is useful for building frontend web applications using frameworks like React. It can also compile to native code via LLVM. This capability allows developers to create native iOS apps that share business logic with Android apps.

Programming in Kotlin involves several distinct structural features. The language supports both object-oriented and functional programming styles. It distinguishes between mutable variables, which can change, and immutable variables, which cannot. In code, these are identified by the keywords "var" and "val." Additionally, Kotlin uses a specific syntax for variable declarations. It places the data type after the variable name, separated by a colon. This design helps align variable names visually, making complex types easier for humans to read.

Kodee-mascot-regular
Kodee-mascot-regular

All classes in Kotlin are public and final by default. This means they cannot be inherited by other classes unless the developer explicitly marks them as "open."

History shows a clear path of intentional design and growth. The first commit to the Kotlin Git repository occurred on November 8, 2010. In July 2011, JetBrains unveiled Project Kotlin after one year of development. The team, including former lead designer Andrey Breslav, wanted a language that compiled as quickly as Java. They looked at the Scala language but found its compilation time was too slow. JetBrains open-sourced the project in February 2012 under the Apache 2 license. The first officially stable release, Kotlin 1.0, arrived on February 15, 2016. This version established a commitment to long-term backwards compatibility.

The significance of Kotlin has grown through major industry partnerships. Google has played a massive role in its adoption. In 2017, Google announced first-class support for Kotlin on Android. On May 7, 2019, Google officially named Kotlin the preferred language for Android app developers. Since the release of Android Studio 3.0 in October 2017, Kotlin has been a standard alternative to the Java compiler. Today, the development costs are borne by JetBrains, while the Kotlin Foundation protects the language's trademark.

Kodee-mascot-petite
Kodee-mascot-petite

Kotlin includes several advanced tools that deepen a programmer's ability to organize code. Extension functions allow developers to add new functionality to existing classes without creating a new derived class. For example, one can add a new method to the String class that appears as if it were always part of the original definition. The language also features "sealed classes." These are classes that restrict their own subclass hierarchies. All subclasses of a sealed class must be defined at compile time, providing strict control over how the code is structured.

Finally, Kotlin connects to broader computer science concepts through its flexible syntax. It supports procedural programming by allowing static methods and variables to exist outside of a class body. It also utilizes "destructuring declarations," which allow a single object to be broken down into multiple variables at once. For instance, a 2D coordinate object can be decomposed into separate X and Y integers instantly. These features, combined with support for string interpolation and the spread operator, make Kotlin a versatile tool for modern software engineering.

669 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (4)
File:Kotlin logo light-on-dark.svg
Kotlin logo light-on-dark.svg
File:Kotlin logo (2025).svg
Kotlin logo (2025).svg
File:Kodee-mascot-regular.svg
Kodee-mascot-regular.svg
File:Kodee-mascot-petite.svg
Kodee-mascot-petite.svg
More to explore

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.