JVM Kotlin preview

Most Kotlin in this track targets the JVM—the same virtual machine as Java. Kotlin source compiles to .class files; you can mix Kotlin and Java in one Gradle or Maven project.

Key JVM concepts

• fun main() in main.kt becomes class MainKt with a static entry point
• Kotlin types map to Java types—Int is int or Integer at boundaries
• @JvmStatic, @JvmOverloads, and @JvmName tune Java-facing APIs
• JDK classes are callable from Kotlin without wrappers

Multiplatform note

Kotlin also compiles to JavaScript and Native (KMP). This track emphasizes JVM patterns; Android teaser links to local Gradle workflows with the Android SDK.

Important interview questions and answers

1. Q: Can Java call Kotlin code?
   A: Yes—Kotlin generates Java-compatible bytecode; expose top-level functions with @file:JvmName or put APIs on objects with @JvmStatic.
2. Q: What runs Kotlin on the JVM?
   A: The Kotlin compiler (kotlinc) emits bytecode executed by the JVM—same as javac output for Java.

Self-check

1. What JVM class name does main.kt typically produce?
2. Can Kotlin use existing Java libraries?

Tip: main.kt becomes MainKt—use @JvmStatic when Java callers need static methods.