public static void main in Kotlin

Question

In Java, especially in Android studio, every time that I want to run or test some Java source code quickly, I will create public static void main (shortkey: psvm + tab) and the IDE will show "Play" button to run it immediately.

Do we have some kind of psvm in Kotlin - an entry point or something in order to run or test anything that quickly? Did try with this function but it wasn't working. (Even try with @JvmStatic). Can we config somewhere in Android studio?

fun main(args: Array<String>) {

}

I think you need to put it inside a companion object with the @JvmStatic annotation. — TheWanderer, Dec 31 '18 at 16:33

score 27 · Answer 1 · answered Dec 31 '18 at 16:40

27

Put it inside a companion object with the @JvmStatic annotation:

class Test {
    companion object {
        @JvmStatic
        fun main(args: Array<String>) {}
    }
}

answered Dec 31 '18 at 16:40

TheWanderer

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3

or even simple `object Test { @JvmStatic fun main(args: Array) {} }` – ssasi Mar 22 '19 at 10:00

leonardkraemer · Accepted Answer · 2018-12-31T16:59:48.470

25

You can just put the main function outside of any class.

In anyFile.kt do:

package foo

fun main(args: Array<String>) {

}

Either main + tab or psvm + tab work if you have your cursor outside of a class.

edited Dec 31 '18 at 16:59

answered Dec 31 '18 at 16:41

leonardkraemer

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Is there a way use it as the main class for the case of running the app as a jar from command line? I only managed to set it up using the companion object + JvmStatic way. – Valerij Dobler Jan 09 '22 at 11:50
I have not done Kotlin development in a while and I cant answer your question off the top of my head, but maybe you find your answer here https://stackoverflow.com/a/44290802/4265739 – leonardkraemer Jan 10 '22 at 13:01

score -2 · Answer 3 · edited Jan 03 '20 at 11:05

-2

Yes, shortkey: main + tab in any kotlin file

It will generate

fun main(args: Array<String>) {

}

edited Jan 03 '20 at 11:05

Misha Akopov

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answered Dec 31 '18 at 16:47

Omar Mainegra

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This does not work inside of a class. (And that was the confusion) – leonardkraemer Dec 31 '18 at 16:53
@leonardkraemer, The question was about how to generate `main` function quickly – Omar Mainegra Dec 31 '18 at 16:55
Thanks @OmarMainegra, main + tab works, so does psvm + tab (outside the class). But @ leonardkraemer's answer looks good to me. – nhp Dec 31 '18 at 17:01

public static void main in Kotlin

3 Answers3