Also related to AoC earlier - does Kotlin have any circular linked list data type or would I just use any Java implementation that I've previously had? My instincts tell me no since most Kotlin collections are based upon the Java ones.

mmm..how do I access to the next element using fold? the operation would be: if next is bigger than the current value

I might be overlooking an obvious solution, but how to convert a

char

to an

Int

?

var.toInt()

returns the ASCII value of the character.

if you want the resulting type to be

Map<String, List<String>>

you’re probably going to have to do some casting

thank you guys for explaining all that 🙂 managed to put it all together and get it working with mapValues

errors.mapValues { (_, v) ->
                     when (v) {
                        is String -> listOf(v)
                        is List<*> -> v as List<String>
                        else -> listOf(v.toString())
                    }
                }

I want to do something like this: mylist.sort { it.popular or not } and then mylist.sort { it.name ascending } in the one list. I want the popular at the top and the rest sorted by name

This blog might help https://proandroiddev.com/understanding-generics-and-variance-in-kotlin-714c14564c47

Hi folks, Suggest me MOOC for kotlin looking for some really good beginner stuff to start with kotlin for Android??Free stuff only??

Hi all guys! Looking for good tutorial for Kotlin + Spring Boot (Notice that I don’t know Spring)

From the guide I know that

lateinit

vars cannot be primitive types. If you're trying to create a bean-compliant class, how do you designate an

Integer

or

Double

type? If you make the property type

Int

you get the error that primitive types can't be

lateinit

, if you give it the type

Integer

you get the warning that you shouldn't use

Integers

but should use

Int

.. And for

Double

there doesn't even appear to be a way to say you want the Object

Double

and not a primitive

double

What's the most idiomatic way to match on the type of multiple expressions? e.g.

class A
class B : A
class C : A

class X
class Y : X
class Z : X

fun example(a : A, x : X) = when(a, x) {
  is B, is Y -> "B and Y"
  is C, is Z -> "C and Z"
  else -> "Not an interesting case"
}

God I knew I would be mad I remember it being an obvious name. Thank you.

Hi, I'm experimenting with kotlin multiproject. There is something that it's not clear to me. My goal is to port a node js project, a simple one ( https://github.com/invasionofsmallcubes/deals-bot ). The idea is to begin with the porting, isolate common code and repository interfaces on the common project, and then create the jvm version using

TelegramBots

(https://github.com/rubenlagus/TelegramBots). The goal is to have two running bots, the js and the kotlin one with one common business logic. I hope it's all clear up to this point. Now the question: for testing, on the node js I used jest + nock. Now I would see, as an advantage, the fact that I can use a java/kotlin mock library (I want to mock the telegram API) inside kotlin test. Of course the library that I will use to implement the bot is a javascript library. So, basically, can I implement my telegram bot in kotlin, using telegram bot js library, and testing it with, as an example, OkHttp MockWebServer?

how to get the time in this format datetime.datetime(2015, 12, 5, 18, 17, 58, tzinfo=<UTC>)

i mean what's a nice way for others to actually download it? perhaps github release zipballs

that's the problem with an api like

ctx.write(Any)

e.g.

ctx.write(response)

in this case. type system can't help

Kotlin doesn't have a ternary operator, use

if(...) then ... else ...

.

Could someone help check out this https://stackoverflow.com/questions/47783929/kotlin-nullibility-check-if-else-functional-approach-how. Thank you!!!

Hi, how can I take elements between two index in a collection? For example, I have a list of 5 elements and I want to take the second to the fourth elements of this list.

I found Kotlin in Action (Manning) to be pretty good.

What is the recommended approach to a first Kotlin project? Start writing Kotlin code in an Android project, or convert an existing Android project written in Java to Kotlin?

what's a good way to quickly bench competing implementations of a function? is there something robust but as simple as running each function in a loop + system.getCurrentMillis(), and then doing it a few times to warm up the jvm?

i am from hyderabad can i get the kotlin hard copy book

Isnt it imported by default with the kotlin.collections package?

well, I converted the whole project to kotlin

i.e (abc){lambda} rather than (abc,{lambda})

Just started this course and I'm uber new programming. Things were going well for me until section which deals with the terminal after stumbling my way through this section I finally have ran into a road block I can't over come these two issues... Can't start Git: C:\Program Files (x86)\Git\git-cmd.exe Probably the path to Git executable is not valid and this Invalid VCS root mappings The following directories are registered as VCS roots, but they are not: <Project> C:\Users....\Desktop\Test

I am to write an SDK and to decide to write with Kotlin or Java. Is there any comparison articles or some sort of guide about best practices on writing APIs in Kotlin that can be called from Java without ugliness? Thanks