Track
kotlin
Kotlin
36 lessons: null safety, coroutines, JVM—kotlinc playground and 108 MCQs.
- Mode
- server_compiled
- Practice
- Compiled runner
- Lessons
- 36 units
Before you start
Kotlin on JVM and multiplatform: null safety, coroutines, and modern syntax over Java.
Preferred language for new Android development and growing server-side adoption.
Android apps, Spring services, and shared KMP modules.
Compiled lessons with Android- and server-oriented examples when published.
After Java or strong OOP background—especially for Android career paths.
Lesson order
Sequential — follow top to bottom36 lessons are live in this track. Start from step 01 for the smoothest path.
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01 intro Introduction to Kotlin
beginner
Open → -
02 what-is-kotlin What is Kotlin?
beginner
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03 kotlin-vs-java-and-others Kotlin vs Java and others
beginner
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04 jvm-kotlin-preview JVM Kotlin preview
beginner
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05 playground-workflow Playground workflow
beginner
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06 hello-world-kotlin Hello, World in Kotlin
beginner
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07 variables-types-kotlin Variables and types
beginner
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08 strings-kotlin Strings and templates
beginner
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09 control-flow-kotlin Control flow
beginner
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10 functions-kotlin Functions
beginner
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11 null-safety-basics Null safety basics
beginner
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12 classes-kotlin Classes in Kotlin
beginner
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13 data-classes Data classes
beginner
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14 inheritance-kotlin Inheritance
beginner
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15 interfaces-kotlin Interfaces
intermediate
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16 objects-companion Objects and companion
intermediate
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17 sealed-classes Sealed classes
intermediate
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18 lists-arrays-kotlin Lists and arrays
intermediate
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19 maps-sets-kotlin Maps and sets
intermediate
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20 lambdas-higher-order Lambdas and higher-order functions
intermediate
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21 extension-functions Extension functions
intermediate
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22 generics-kotlin Generics
intermediate
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23 delegation Delegation
intermediate
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24 exceptions-kotlin Exceptions
intermediate
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25 coroutines-intro Coroutines introduction
advanced
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26 flows-intro Flows introduction
advanced
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27 scope-builders Coroutine scope builders
advanced
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28 kotlin-stdlib-tips Kotlin stdlib tips
intermediate
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29 packages-imports-kotlin Packages and imports
intermediate
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30 gradle-intro Gradle introduction
intermediate
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31 file-io-kotlin File I/O
intermediate
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32 testing-kotlin Testing in Kotlin
intermediate
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33 java-interop Java interoperability
intermediate
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34 android-teaser Android teaser
advanced
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35 interview-essentials-kotlin Interview essentials
advanced
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36 production-checklist-kotlin Production checklist
advanced
Open →