Out of interest how does this slack relate to the 'official' one? I actually prefer the channels here. They are spot on 🙂.

Doing JetBrains Basic Kotlin and it does not like the formatting of the first 3 val statement.

fun main() {
    val min_sleep: Int = readln().toInt()
    val max_sleep: Int = readln().toInt()
    val hours_slept: Int = readln().toInt()

    println(
        if (hours_slept < min_sleep) {
            "Deficiency"
        } else if (hours_slept > max_sleep) {
            "Excess"
        } else {
            "Normal"
        }
    )
}

Variable names should match the pattern: [a-z][A-Za-z0-9]* What am I missing?

Does anybody know how to make "Show kotlin bytecode" in Itnellij IDEA work with kotlin multiplatform? For me, it just displays an error, while working fine for non-kotlin multiplatform projects

Still learning about generics. In this example I would expect this to work, because I feel like

Animal<Int>

fits into

Animal<Any?>

. What am I missing?

open class Animal<T>
class Dog: Animal<Int>()
val x : Animal<Any?> = Dog() // error at the constructor call

Hi, I had a question about idiomatically returning a value from a callback function in Kotlin. In option A below I don’t need any qualified return and looks less “weird” to me. However, in other langs I usually see advocation of moving conditions “left”. So in B I’ve tried this. But now I need a qualified return in the condition. I have a feeling A is more idiomatic in Kotlin because we don’t need to unnecessarily add the qualified retun but this also goes against my desire to move as much “left” as possible 😅. Is there another way?

// A)

validate { credential ->
    // ...
    if (/* ... */) {
        Some("thing")
    } else {
        null
    }
}

// B)

validate { credential ->
    // ...
    if (/* ... */) {
        return@validate Some("thing")
    }

    null
}

Probably a newbie question? I have 2 enums that cross-reference each other

enum class School(val zone: String, val captain: Student) {
    Metricon("New York", Student.David),
    Carlisle("London", Student.Paul)
}

enum class Student(val lastName: String, val school: School) {
    David("Samuel", School.Metricon),
    Solomon("Handsome", School.Metricon),
    Saul("Black", School.Metricon),
    Paul("Lewis", School.Carlisle),
    Joseph("Hardy", School.Carlisle),
    John("Baptise", School.Carlisle),
}

When I print it out

val student = Student.David
        val school = School.Carlisle

        println(student.school)
        println(school.captain)
        println(student.lastName)
        println(school.zone)

It resulted in

Metricon
null
Samuel
London

Notice the

null

there. The

school.captain

is missing and became null. How can I solve this problem?

Hi, I saw a

kt

file with an

object

inside an

object

. I would like to know if someone can help me to understand the difference between using the

object

and a

companion object

. Is this the right way to use

object

?

object Type {
    object USER {
        const val KEY  = "key"
        const val NAME  = "name"
    }
}

Ran into some very strange behavior. Why does it matter when I call

::class

?

val c1 = Int::class.java to 42::class.java 
c1.first to c1.second // (int, int)

val c2 = Int::class.java to 42
c2.first to c2.second::class.java // (int, class java.lang.Integer)

👋 Hello, team!

i need a mentor to help mei

i am right now completing the courses and codelabs present in android courses

When you have code at the top level of a file named FileName.kt, Kotlin creates a class named FileNameKt by default. This is where MainKt comes from. However, you have Main.kt in a package named cinema, so you should use cinema.MainKt

TLDR: The JetBrains Academy Basic Kotlin course is causing me to lose the will to live (I've done lots of courses and non have had this effect on me). Can someone please recommend an alternative one for Basic Kotlin? The below seems like a bit of a stretch. "In other words, the

=

sign does not copy the object itself, it only copies a reference to it.". This only seems the case for immutable objects. if I made the variable a var this is not the case. This seems very important. I'm getting very disillusioned with the JetBrains Academy course. It's very slow going but still manages to seem to oversimplify things. Can anyone recommend a good beginners course with lots of excursuses? So far my favourite one is https://www.udemy.com/course/100-days-of-code/ (bit its a Python course). It covers a lot and the docent is not too bogged down with the fiddly, not very useful stuff. I really appreciate the effort they put in but I want something that is a bit more fun. I don't mind paying a bit.

Hello, I am sorry to ask these simple questions. I need to know that , the jvm that kotlin run its code in it belongs to any company??? And if the company that owns jvm blocked the kotlin to use it what will happen here?? Thank you

Curios, for constants you use 'const val', why not just const?

is there a shorter way of writing this?

val names = ArrayListQueue<String>()

    map["you"]?.forEach{
        names.enqueue(it)
    }

Is there a way to subdivide kotlin multiplatform project into modules? Aka, so code from one module can't use code from other module unless its module depends on that other module. I know that I can do localmaven and publishing, but I still want to keep it all inside one project so I can edit code from one IntelliJ IDEA instance, and all the maven stuff seems like an overkill

If you implement a Java interface that defines a getter:

interface Something {
  String getAConstant();
}

and you want the value of

getAConstant

to be a constant, is there a less verbose way than this?

class ConcreteSomething : Something {
  private val _constant = "constant value"
  override fun getAConstant(): String = _constant
}

(It's not actually a String, it's calculated by calling other methods on a supertype using a constructor value, just simplifying things.)

In kotlin how to create a String say “hello” twice in heap memory? In java, we do this with the help of ‘new’ keyword : new String(“hello”)

Hello, I would like to implement the class delegation pattern by delegating to a property which is initialized during class initialization. I think technically this should work but Kotlin 1.7.10 doesn’t accept this construct. The reason why I want to delegate to a property is because when I create an instance of the delegate, I need to access an extension value which is declared in a third-party library. Is there an alternative besides having to implement the delegation manually? Is this something that a future version of Kotlin might support?

class Derived(
    factory: (dep: Dependency) -> Base,
) : SomeBaseClass(), Base by delegate {

    private val delegate = factory(dependency)
}

val SomeBaseClass.dependency: Dependency
  get() = ...

If I have a class in

commonMain

that I want to provide specific implementation on ONLY ONE multiplatform target, while using default common implementation for other, is there a way to do it without making class

expect

and spamming

actual

in every target?

Hello. I am coming from JS world and want to ask two things: 1. how to replace / from start string? i have path /path/something and want to remove first slash. Tried with

path.replace("/^\\/|\\/\$/g".toRegex(), "")

does not work. 2. what is easiest way to get search params as key value pair. /path/something?boom=true&id=bam. Want to have search params like boom:true , id: bam?

it appears to me that kotlin is more sensitive at the class level, at order of operations? it seems to process class files/fields vertically. I don't recall java having as many cases as this does. But for instance, a class level property being referenced by the init {} block, the property must be above. is this behavior actually different, or just something i haven't run into enough before? What is it called?

Does Kotlin have an equivalent of the new Java feature:

if (obj instanceOf String myString) {
  // myString
}

I know I can do

as

and get a smart cast but I can’t give it a new name in Kotlin, right?

class CliOption2<T>(additionalProperties: MutableMap<String, Any>) {
        val value by lazy {
            val t = additionalProperties[cliOption.opt]!! as? T
            t ?: throw NotImplementedError("cli option could not be casted")
            t

} how can i fix the cast warning here? I thought me throwing something if it fails would work. Why is it still considered unsafe and how can i fix this?

Hi all, I am wondering what testing framework are you using in the project now, like mockk/mockito/kotest~~~

Hey team is there any channel for KMM platform.

Hey everyone! Silly question: is there a channel for 'Kotlin' itself ?! 😄 I'm looking for docs/conventions/ideas about when to use

if

and when to use

when

as the line between these two are very thin and we want to have an agreement in our team about their usage.

Is there a find or throw method on lists?