Questions tagged [kotlin-function-type]
10 questions
4
votes
1 answer
kotlin passing function as argument got Type mismatch, Required: ()->Unit, Found: Unit
Having a function which takes function type for the callback
fun dataBtnClickHandler(callbackFunc: () -> Unit){
// do something
......
// call the callback function
callbackFunc
}
And there is a function defined as
private…
lannyf
- 6,775
- 4
- 49
- 92
3
votes
3 answers
Why are there two functions which do the exact same thing? Why must be invoked differently in Kotlin?
fun main() {
fun evenFn(num: Int): Boolean {
return num % 2 == 0
}
val evenFn = fun(num: Int) = num % 2 == 0
val list = listOf(1, 2, 3, 4, 5, 6)
println(list.filter(evenFn))
println(list.filter { evenFn(it) })
}
How…
Shubhang B
- 59
- 1
- 3
2
votes
0 answers
How To Obtain An Annotation Of A Function Literal At Runtime
package _z_additional
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.TestInstance
import kotlin.reflect.KFunction
import kotlin.reflect.full.declaredMemberFunctions
import…
Sero
- 1,572
- 1
- 15
- 29
2
votes
3 answers
Why String.() -> Unit is the same as (String) -> Unit in my code?
I am struggling to understand how a function type with receiver works in Kotlin. I don't understand why we can use (String) -> Unit and String.() -> Unit in my code indistinctively
fun main() {
var showStringFunction1: (String) -> Unit =…
Marti Serra Molina
- 173
- 6
1
vote
2 answers
How do I provide an implementation for a function type?
Concerning function types in Kotlin
The following gives exception kotlin.UninitializedPropertyAccessException: lateinit property foo has not been initialized
class SomeClass (){
lateinit var foo: (String) -> Int
}
val result : Int =…
Jim
- 2,341
- 1
- 11
- 23
1
vote
2 answers
Call Higher Order function of Kotlin from Java
Kotin Class
class LoginService{
fun getLoginData(loginData: String) {
request(LoginApi.create().getLoginData(loginData))}
}
fun changePassword(_:String){
request(LoginApi.create().changePassword(_)
}
class…
Sachin Kasaraddi
- 581
- 3
- 12
0
votes
1 answer
Inherit function type in Kotlin
Is there a way in Kotlin to inherit function types?
What I want is to have a member like so: private lateinit var onPickedFunc: (Any) -> Task? so I can dynamically store the functions I need to run after a user has made it's choice. For…
Omer Levy
- 75
- 1
- 7
0
votes
2 answers
Why should I implement a function type as an interface in Kotlin
I came across something and wondered all the time why you should do this.
You implement an interface in Kotlin through a simple function type:
"It is possible for a class to implement a function type as if it were an interface. It must then supply…
Torben G
- 641
- 7
- 21
0
votes
1 answer
Kotlin and how to convert an if/else to functional approach?
I have a function in this format:
fun myFunction(param1: Int, param2: String, param3: Number): Number =
if(param1 < NUMBER) {
if(param2 == "FOO") {
// code for result
} else {
// code for result
…
Jim
- 2,341
- 1
- 11
- 23
0
votes
2 answers
Extension function on a generic type
I am new in Kotlin and I am trying to understand type alias and functions.
I have the following example:
interface EmptyInterface
typealias GenericCase = T.(EmptyInterface) -> T
val myFunctionVariable: GenericCase = {
_ -> "Hello…
Jim
- 2,341
- 1
- 11
- 23