Kotlin Programming Language

Kotlin is a modern programming language developed by JetBrains and first released in 2011, designed as a concise, safe, and expressive alternative to Java with full interoperability, officially supported by Google for Android development since 2017 and now the preferred Android language, adopted by Google, Amazon, Atlassian, Pinterest, and Uber. The Java interoperability enables calling Java code from Kotlin and vice versa without wrappers, allowing gradual migration of existing Java codebases file by file, while frameworks including Spring, Hibernate, and Android SDK work seamlessly. The null safety system distinguishes nullable and non-nullable types at compile time, preventing null pointer exceptions with safe call operators, Elvis operators, and smart casts. The concise syntax reduces boilerplate through data classes auto-generating equals and hashCode, sealed classes for restricted hierarchies, extension functions for adding methods to existing classes, smart casts, string templates, and when expressions for pattern matching. The coroutines provide lightweight asynchronous programming with suspend functions, structured concurrency, and flow for async streams. The Kotlin Multiplatform enables sharing code across iOS, Android, web, and desktop. Designed for Android developers, JVM developers, and cross-platform teams.