Kotlin Get Started

Getting started with Kotlin is writing a program file, compiling it, and running the compiled program.

This file holds one statement inside main. The statement shows one line.

fun main() {
    println("Ready")
}

Step one appears above Step two in the output. The order on screen matches the order in the file.

fun main() {
    println("Step one")
    println("Step two")
}

This file holds two statements. Each statement shows its own line.

fun main() {
    println("My program")
    println("It works")
}

Example

fun main() {
    println("Program starts")
    println("Program ends")
}

The program file in this course is main.kt.
JVM: a program that runs compiled code on a computer.
Use kotlinc main.kt -include-runtime -d main.jar to compile the file into main.jar.
Use java -jar main.jar to run main.jar on the JVM.
A statement is one complete instruction in a program.
Statements run from top to bottom.

In this example, the first statement shows Program starts. The second statement shows Program ends below the first line.

Edit the code, then press Run.

Running is simulated · Kotlin Playground

fun main() {
    println("Program starts")
    println("Program ends")
}

Which command compiles the file main.kt?

main.kt kotlinc java -jar main.jar kotlinc main.kt -include-runtime -d main.jar println main.kt