Kotlin Setup and First Program

Install the JDK

Kotlin needs a JDK 17+ underneath. Verify with java -version, then pick one path below.

Option 1: IntelliJ IDEA (Recommended)

• Install IntelliJ Community (free) - Kotlin plugin is built in.
• New Project, language Kotlin, build system IntelliJ or Gradle.
• Write main.kt, press Run - zero configuration.

Option 2: Command Line Compiler

# install via SDKMAN or brew, then:
kotlinc hello.kt -include-runtime -d hello.jar
java -jar hello.jar

Option 3: Online Playground

Learn syntax instantly at play.kotlinlang.org - no install at all. Perfect for the first five lessons of this tutorial.

Your First Program

fun main() {
    println("Hello, GroovyGrails learner!")
}

No classes, no semicolons, no public static void ceremony.

Key Points

• IntelliJ gives the smoothest start; playground is fastest.
• Every example here runs with plain kotlinc too.
• Always match the JDK version to your tutorial series.