What Is Kotlin? The Modern Language for Android
SkillVeris Team
Engineering Team
Kotlin is a statically typed language that runs on the Java Virtual Machine and interoperates directly with existing Java code.
In this guide, you'll learn:
- Google named Kotlin its preferred language for Android development, replacing Java as the default choice for new apps.
- Kotlin's null safety system catches many null pointer errors at compile time rather than at runtime.
- Concise syntax lets Kotlin express the same logic as Java in noticeably fewer lines of code.
- Kotlin Multiplatform allows sharing business logic across Android, iOS, and other targets from a single codebase.
1What Is Kotlin?
Kotlin is a statically typed programming language that runs on the Java Virtual Machine and was created by JetBrains as a more concise, safer alternative to Java.
It compiles to the same bytecode as Java, which means Kotlin code can call Java libraries directly and Java code can call Kotlin code, making adoption in existing projects gradual rather than all-or-nothing.
2Why Kotlin Was Created
Kotlin was designed to fix long-standing pain points in Java, particularly verbose syntax and the frequency of null pointer exceptions in production code.
JetBrains built it as a pragmatic, interoperable language rather than a clean-slate rewrite, so teams could adopt it file by file inside an existing Java codebase instead of rewriting everything at once.
3Key Features of Kotlin
A handful of language features distinguish Kotlin most clearly from Java.
- Null safety: the type system distinguishes nullable and non-nullable types, catching many null errors at compile time.
- Concise syntax: data classes, type inference, and lambda expressions reduce boilerplate significantly.
- Full Java interoperability: Kotlin and Java code can coexist and call each other in the same project.
- Coroutines: a lightweight approach to asynchronous programming built into the language.
- Extension functions: the ability to add new functions to existing classes without inheriting from them.
4Kotlin vs. Java
Kotlin generally requires less code than Java to express the same logic, largely due to features like data classes and type inference that eliminate repetitive boilerplate.
Java remains more widely taught and has a longer track record in large enterprise systems, while Kotlin is favored for new Android development and projects that value conciseness and null safety.
Interoperability in Practice
Because both languages compile to the same bytecode, a single Android project can mix Kotlin and Java files, which is exactly how most real-world migrations from Java to Kotlin happen: gradually, module by module.
5Where Kotlin Is Used
Kotlin's biggest use case remains Android app development, where Google has designated it the preferred language, but its footprint extends beyond mobile.
- Android app development, the primary and most common use case.
- Backend web services, using frameworks like Ktor or Spring Boot with Kotlin support.
- Cross-platform mobile development through Kotlin Multiplatform, sharing logic between Android and iOS.
- Data pipelines and scripting, taking advantage of Kotlin's concise syntax and JVM ecosystem access.
6How Hard Is Kotlin to Learn?
Developers with prior Java or general object-oriented programming experience typically pick up Kotlin quickly, since the core concepts carry over directly.
Complete beginners can also start with Kotlin directly; its safer defaults and more readable syntax make some common Java mistakes simply impossible to write.
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7Getting Started With Kotlin
Android Studio comes with Kotlin support built in, so starting a new Android project in Kotlin requires no extra setup.
Anyone building toward Android development or exploring modern JVM languages will find Kotlin a practical next step, with deeper language coverage available in SkillVeris's programming language study notes and topic guides.
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About the Publisher
SkillVeris Team
Engineering Team
Our engineering writers turn abstract code concepts into hands-on, project-driven learning experiences.
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