logo
down
shadow

KOTLIN QUESTIONS

How to implement this kotlin ReceiveChannel code properly
How to implement this kotlin ReceiveChannel code properly
will be helpful for those in need The reason why it is recommended to declare your function as extension of CoroutineScope is that you need a scope for any coroutine-creating built-in function anyway. You should not be able to call produce without a
TAG : kotlin
Date : January 12 2021, 07:00 PM , By : Naveen
How to initialise 'MutableMap' from constructor of data class in kotlin?
How to initialise 'MutableMap' from constructor of data class in kotlin?
should help you out You can do one of the following: Extracting the init logic into a companion function:
TAG : kotlin
Date : January 12 2021, 01:40 AM , By : phatfish
Implementing flow for Updation of state , do we have to use SendTransaction
Implementing flow for Updation of state , do we have to use SendTransaction
I wish did fix the issue. SendTransactionFlow is called in FinalityFlow. No need to call separately. See in below link - https://github.com/corda/corda/blob/master/core/src/main/kotlin/net/corda/core/flows/FinalityFlow.kt
TAG : kotlin
Date : January 11 2021, 05:14 PM , By : Shitic
What is the difference between "package" and "module" in Kotlin?
What is the difference between "package" and "module" in Kotlin?
may help you . Short answer: packages collect related classes, and correspond roughly to directories; while modules are a much higher level and correspond to projects and/or compiler runs.Longer answer:
TAG : kotlin
Date : January 11 2021, 03:32 PM , By : Thx1138.6
About type parameter of generic in Kotlin
About type parameter of generic in Kotlin
wish help you to fix your issue First, to distinguish T : Comparable and T : Comparable, take a look at the following example. The difference is whether you can compare T with T?.
TAG : kotlin
Date : January 07 2021, 07:50 AM , By : ugufugu
How to set values to data class if some size is specified in kotlin?
How to set values to data class if some size is specified in kotlin?
it helps some times I have a data class in kotlin like this: , It's possible:
TAG : kotlin
Date : January 02 2021, 10:54 PM , By : judith
Kotlin decomposing numbers into powers of 2
Kotlin decomposing numbers into powers of 2
hope this fix your issue Hi I am writing an app in kotlin and need to decompose a number into powers of 2. , Hi I finally managed to get this working properly:
TAG : kotlin
Date : January 02 2021, 10:54 PM , By : Asbie
How to simply add another source to MediatorLiveData in kotlin?
How to simply add another source to MediatorLiveData in kotlin?
may help you . I want to combine multiple data sources in a MediatorLiveData. Unfortunately, there are not many examples yet. So in my ViewModel I have , Having done quite some research.. I found it out. Here is an example
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : CHeMoTaCTiC
How to avoid nest 「null check」by "?.let"?
How to avoid nest 「null check」by "?.let"?
wish helps you There are extension functions out there to achieve what you're looking for, you can find them in this thread https://discuss.kotlinlang.org/t/kotlin-null-check-for-multiple-nullable-vars/1946But honestly, you're probably better of just
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Angel Paunchev
Idiomatic way in kotlin to transform/append to a list?
Idiomatic way in kotlin to transform/append to a list?
To fix this issue While your solution is quite readable, it copies all of the items of the original List on every iteration of the for-loop, as += on a var newList: List will create a new list each time. The computational complexity of the worst case
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : ziqew
Extension property inside class: Unresolved reference: errorResponse
Extension property inside class: Unresolved reference: errorResponse
With these it helps This is because the errorResponse extension is only available in the context of the companion object of TransportService when you define it there.If your extension function doesn't need the companion's properties or methods, there
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : David B
How to extend enums in Kotlin?
How to extend enums in Kotlin?
may help you . There is more to the reason why enum inheritance is not supported than "inheritance is evil". In fact, a very practical reason:
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : ikey
Convert Long to String in Kotlin
Convert Long to String in Kotlin
seems to work fine What am I missing here? , You could use Kotlin String templates:
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Jim F.
Kotlin: Should mutableList be declared as Val or Var?
Kotlin: Should mutableList be declared as Val or Var?
I hope this helps you . I think it's declared as val because the list will be the same always, the only thing that changes is it's elements. You'll never do something like:
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Thierry Brunet
kotlin, where the return from inside the let go
kotlin, where the return from inside the let go
will help you The rule in Kotlin is that a plain return returns from the nearest fun.See the docs here.
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Paul McKee
Check if any array item is not empty
Check if any array item is not empty
I think the issue was by ths following , No, you can't tell how many element in an array are empty without visiting them. You can use any and all, both of which iterate internally though:
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : user118656
How can i call an interface in kotlin?
How can i call an interface in kotlin?
wish helps you The SpeechService.Listener { } syntax for SAM interfaces is only possible when the interface is written i Java (see https://kotlinlang.org/docs/reference/java-interop.htmlsam-conversions). Because the interface is written in Kotlin, yo
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Juan Pablo
Kotlin test, how to run BeforeEach with DescribeSpec test style
Kotlin test, how to run BeforeEach with DescribeSpec test style
help you fix your problem On the new version of KotlinTest 3.3 there are new Listeners to define beforeTest, afterTest, beforeSpec and so on.In this case a posible solution should be:
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : user158193
Convince Kotlin compiler map has a key
Convince Kotlin compiler map has a key
this one helps. Kotlin Collections already defines the Map.getValue() extension function, which returns an element with non-nullable type or throws NoSuchElementException.Now this will compile fine:
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Frank Bradley
how do you declare static property in kotlin?
how do you declare static property in kotlin?
To fix this issue
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Pepe Araya
Why I Cannot Access to this function?
Why I Cannot Access to this function?
This might help you You're calling getComplicationId like a static method, but it's an Instance method instead. To solve, put that method (and the variables it uses) inside a Companion Object :
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Grant
Kotlin - How do I concatenate a String to an Int value?
Kotlin - How do I concatenate a String to an Int value?
should help you out $ dollar – Dollar symbol is used in String templates that we’ll be seeing next
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Eran Yahav
Lambda as a function parameter -> accept methods only from particular class
Lambda as a function parameter -> accept methods only from particular class
around this issue For this, functions simply aren't an appropriate type. I'd declare a type whose values correspond to methods of S, so
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : kema
Kotlin inline class in JUnit tests
Kotlin inline class in JUnit tests
it should still fix some issue What you probably wanted to do was val name = nameInlineClass.value, but I'll try to explain the error.See Representation from docs (includes code sample):
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Revision17
How can Kotlin's Set be covariant when contains() takes E?
How can Kotlin's Set be covariant when contains() takes E?
like below fixes the issue Declaration-site covariance in the form of the out modifier misses a useful use case of making sure that an instance passed as an argument is generally sensible to pass here. The contains functions are a good example.In the
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : gbodunski
How to split on unicode whitespace in kotlin
How to split on unicode whitespace in kotlin
Any of those help Since Java 7 Pattern allows to specify the UNICODE_CHARACTER_CLASS-flag which would basically also work for your current issue:
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Willem van Schevikho
This annotation is not applicable to target member property without backing field or delegate
This annotation is not applicable to target member property without backing field or delegate
Hope this helps Try using @get:Provides instead of just @Provides on the var cookie.EDIT:
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : changke
How to check if a string is a valid email in android?
How to check if a string is a valid email in android?
I wish this help you Based on this answer in java (How should I validate an e-mail address?), you can use extension function to check the validity in kotlin.
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Tom
Please Explain to me this kotlin statement?
Please Explain to me this kotlin statement?
hope this fix your issue this@A is called a qualified this, and it is shortly documented here.this@A is used to access the outer object of type A. Because B is an inner class, instances of B have to be created using an instance of the enclosing class
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : hsdfhksh
How to use kotlin's default parameter only if the input is not null?
How to use kotlin's default parameter only if the input is not null?
help you fix your problem Depends on what you mean by less verbose.One way is using the null-safe-operator (?.) and something like let:
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Chris Lomax
Proposed change of `equals` to `==` can't be applied to Char and String?
Proposed change of `equals` to `==` can't be applied to Char and String?
will help you Just to be sure we're on the same page, it is a Char because the filter method that you use operates on the string as a sequence of characters. Therefore, it.equals("a") is effectively comparing a Char with a String. This can never be t
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : amy
Issue when trying to import Jacoco code coverage to SonarQube: Cannot import coverage information for file, coverage dat
Issue when trying to import Jacoco code coverage to SonarQube: Cannot import coverage information for file, coverage dat
this will help I'm having some issues when trying to import Jacoco code coverage to SonarQube. , Search in Google by keywords sonarqube kotlin jacoco and
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : TomL
brief function code for null check in kotlin
brief function code for null check in kotlin
this will help Whenever I see code with a lot of conditional logic, I try to remember that I can "push" nulls rightward. Instead of handling if/else every time you need to test for null, imagine that you just take what you want (happy path) and pass
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Wilfred Knigge
How to capture an argument that was passed to a mocked function and return it?
How to capture an argument that was passed to a mocked function and return it?
hope this fix your issue So in the service I am testing, I have a depending service which is taking an object and does some augmenting on it. I want to mock the part the depending service is doing and make the mock return exactly what it's receiving.
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Marianisho
Kotlin, unresolved reference on everything in VSCode
Kotlin, unresolved reference on everything in VSCode
wish helps you I had this issue when I had both the Kotlin Language by mathiasfrohlich and Kotlin by fwcd extensions installed. Uninstalling Kotlin by fwcd resolved the problem in my case.
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Amin Amini
Webflux saving to repository without using .block()
Webflux saving to repository without using .block()
Any of those help Use flatMap to chain your functions: it.map { product -> product.active = active }.flatMap(repository::save)
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : moss
takeWhile which includes the actual value matching the predicate (takeWhileInclusive)
takeWhile which includes the actual value matching the predicate (takeWhileInclusive)
I wish this help you I did not find a suitable existing function yet and I also do not really like the linked solution, so I played around a bit and ended up with the following extension function:
TAG : kotlin
Date : January 02 2021, 06:48 AM , By : Tony Siu
Kotlin - object type check against HashMap<String, String> shows warning
Kotlin - object type check against HashMap<String, String> shows warning
With these it helps Actually, you cannot check that your object has type HashMap because type parameters are erased in runtime. I would like to suggest you just use a safe cast:
TAG : kotlin
Date : January 02 2021, 06:36 AM , By : orlandoferrer
Primitive properties initialization in Kotlin
Primitive properties initialization in Kotlin
it helps some times I have immutable Int property which value is caclulated in the constructor.Something like this: , Why not doing it while initialization?
TAG : kotlin
Date : January 02 2021, 05:23 AM , By : user124112
How can I improve readability of this Kotlin code?
How can I improve readability of this Kotlin code?
will help you You should create a function that you can repeat for each of your lists. Like this:
TAG : kotlin
Date : January 02 2021, 05:23 AM , By : Rohii
How to parse JSON objects into an enum
How to parse JSON objects into an enum
it should still fix some issue I have a JSON object that is something like , You can create a deserializer for TspEnum:
TAG : kotlin
Date : January 02 2021, 04:59 AM , By : 3NZ0
Can I get a TableView column to use a Kotlin Exposed transaction when referencing a property?
Can I get a TableView column to use a Kotlin Exposed transaction when referencing a property?
around this issue , Edvin, for reminding me that columns work on the UI thread and that it shouldn't be doing the heavy lifting! I tried a few other things with mapping, hoping that the choke point was the amount of transactions I was doing, but it d
TAG : kotlin
Date : January 01 2021, 05:13 PM , By : AdrianB
How can I perform clean up actions upon closing a view in Kotlin/TornadoFX?
How can I perform clean up actions upon closing a view in Kotlin/TornadoFX?
this will help I'm using this in my project right now. setOnCloseRequest is my go to!
TAG : kotlin
Date : January 01 2021, 05:13 PM , By : Salikh
How to deal with nullable variables that are not null?
How to deal with nullable variables that are not null?
I wish this helpful for you Well, this piece of code works if foo is a local variable. I guess, your code looks a little bit different and foo is a field of a class. The solution is simple: use let:
TAG : kotlin
Date : January 01 2021, 05:13 PM , By : Per
Defining a mutable property with a custom setter
Defining a mutable property with a custom setter
should help you out UPD: as @PaulHicks noted, in the first example, age is not a property, it's just a constructor parameter with the same name, and the property age is declared in the body and then just initialized from the constructor parameter. Yo
TAG : kotlin
Date : January 01 2021, 05:13 PM , By : user176445
Kotlin combined usage of arrow, lamda, ?, . , and let. what it mean?
Kotlin combined usage of arrow, lamda, ?, . , and let. what it mean?
this will help , dto.someMap[MAP_A]?.let(::setAId) can be expanded like
TAG : kotlin
Date : January 01 2021, 05:01 PM , By : user121350
Is it possible to extend a base class in a data class without overriding parameters?
Is it possible to extend a base class in a data class without overriding parameters?
I hope this helps you . Having a base class like this and a derived data class, you have to override its properties or separate them, because all primary constructor parameters of a data class must also be declared as properties:
TAG : kotlin
Date : January 01 2021, 06:46 AM , By : Lars
Access a value from a Kotlin script using jsr-223
Access a value from a Kotlin script using jsr-223
Any of those help Solved by creating a function that returns the value, and calling that function.
TAG : kotlin
Date : December 31 2020, 08:18 AM , By : gcomstock
Single method to launch a coroutine
Single method to launch a coroutine
around this issue Hmm.. Maybe I misunderstand you but it seems you can just pass a block of code as lambda function like this:
TAG : kotlin
Date : December 31 2020, 04:56 AM , By : Matt Watson
The value of NumberPicker doesn't change
The value of NumberPicker doesn't change
it helps some times I'm a beginner in android and Kotlin. I want to get string values I set as displayedValues from NumberPicker. I tried, but It only returns Int numbers. , The translation of the answer there to Kotlin is
TAG : kotlin
Date : December 28 2020, 06:11 AM , By : Ryan Adriano
MutableSet don't prevent duplicated content when using sealed class
MutableSet don't prevent duplicated content when using sealed class
wish of those help A MutableSet checks whether it contains an element by using the elements' equals checks and, depending on the implementation, hashCode. A HashSet, for instance, uses hashCode to store and quickly lookup the elements in a hash table
TAG : kotlin
Date : December 27 2020, 04:18 PM , By : changke
Why 'is' keyword only work with open classes in kotlin?
Why 'is' keyword only work with open classes in kotlin?
this one helps. My question might be noob but please help me. I don't understand what is purpose of not allowing non-open classes with "is" keyword in kotlin. , When you write it like this
TAG : kotlin
Date : December 27 2020, 03:39 PM , By : matthew
Extension function override of `equals(Any?): Boolean`
Extension function override of `equals(Any?): Boolean`
I wish this help you A Java dependency defines some value classes without equals methods. They really should implement it, but they don't. , You can't override a method using an extension function.
TAG : kotlin
Date : December 25 2020, 11:30 PM , By : lewing
How to check a string starts with a specified string in kotlin?
How to check a string starts with a specified string in kotlin?
will help you I want to check a string is starting with a particular string or not, how can check that in kotlin
TAG : kotlin
Date : December 25 2020, 11:01 PM , By : dormsbee
Generate data class attribute value only during creation
Generate data class attribute value only during creation
wish of those help Try to make supplierId as a constructor parameter with the default value like this:
TAG : kotlin
Date : December 25 2020, 09:01 PM , By : arbeitandy
Redirect to absolute URL in Ktor
Redirect to absolute URL in Ktor
seems to work fine I'm learing how to work with ktor. For a special use case i need to redirect to a different domain from my ktor server. However i cant get it to work rigth now. , Figured it out. You need to set also the protocol. This works
TAG : kotlin
Date : December 25 2020, 09:01 PM , By : jonagh
how do I readirect t another path
how do I readirect t another path
it helps some times I have this code and I want to forward to another path when id == 1 , You can just use call.respondRedirect:
TAG : kotlin
Date : December 25 2020, 08:30 PM , By : tanminivan
How to limit allowed file size (multipart-file) in Ktor
How to limit allowed file size (multipart-file) in Ktor
fixed the issue. Will look into that further There's nothing out-of-the-box, AFAIK.But you can take inspiration from the official example: https://ktor.io/servers/uploads.html
TAG : kotlin
Date : December 25 2020, 08:01 PM , By : ranja
nested let blocks in kotlin and valiadation
nested let blocks in kotlin and valiadation
it fixes the issue I want to handle validation in functional approach. I have user validation logic as below , In the inner block
TAG : kotlin
Date : December 25 2020, 05:02 PM , By : Salikh
Generic method for finding instances of classes with 'is' operator
Generic method for finding instances of classes with 'is' operator
around this issue I agree with @dyukha. It's pretty convenient to use reified type parameters here. With it you can rewrite your function like:
TAG : kotlin
Date : December 25 2020, 04:01 PM , By : anon

shadow
Privacy Policy - Terms - Contact Us © scrbit.com