import kotlinx is impossible in IntelliJ IDEA - kotlin

Question

I`m testing coroutine example code on IntelliJ IDEA. But I cannot import library which needs for coroutine.
I created project as Kotlin - "JVM | IDEA". I tried simple print hello world code and succeesfully done. But coroutine example don`t even execute.
import kotlinx.coroutines.launch
import kotlinx.coroutines.runBlocking
import kotlinx.coroutines.sync.Mutex
import kotlinx.coroutines.sync.withLock
fun main()
{
runBlocking {
var counter = 0
val lock = Mutex()
val coroutines = List(3) {
launch {
repeat(1_000) {
lock.withLock {
counter++
}
}
}
}
coroutines.forEach { it.join() }
println("Final counter: $counter")
}
}
This Code runs on https://play.kotlinlang.org. But in IDEA, they cannot understand it, showing 'Unresolved reference'.
I`ve searched but no answer found. How can I run this on IDEA project?

Answer 1

it would be a good idea to switch to a Gradle-based build, which will automatically be imported by IntelliJ IDEA.
you can set IntelliJ to automatically stay in sync with your Gradle files, or you can opt to "sync" IntelliJ to Gradle's structure on demand.
you have two syntax options with Gradle: Groovy and Kotlin. make sure if you are new to Gradle that you use a consistent syntax, otherwise it can be hard to follow the guides. obviously if you are working in Kotlin, it's a great idea to use Kotlin in your build files, too.