If I have: ```interface Foo { fun printlog(msg: String) = "... - $msg" } class Bar : Foo``` How ...

# getting-started

[dave08]

If I have:

interface Foo {
   fun printlog(msg: String) = "... - $msg"
}

class Bar : Foo

How can I get the printlog in the interface to print out Bar - some message? If I use ${this::class.simpleName} it just gives me the interface's name...

[Joffrey]

Using ${this::class.simpleName} does work: https://pl.kotl.in/3LrWAHRvp

interface Foo {
   fun printlog(msg: String) = "${this::class.simpleName} - $msg"
}

class Bar : Foo

fun main() {
   val log = Bar().printlog("hello")
   println(log)
}

This correctly prints Bar - hello

[Joffrey]

I believe you might be calling printlog on something that's not an instance of Bar maybe?

[dave08]

I have:

interface BaseResult {
    fun toLogFmt(): String =
        "type=${this::class.simpleName} literal=${toString()}"
}

[dave08]

And:

fun interface ResultUseCase2<in Request : Any, out Result : BaseResult> : UseCase<Request, Result> {
    suspend fun doAction(request: Request): Result

    override suspend fun invoke(request: Request): Result =
        doAction(request).also { <http://logger.info|logger.info> { it.toLogFmt() } }
}

[dave08]

And I get UseCase instead of the type of result... my results are a sealed interface inherited from BaseResult and data classes inhereted from the sealed interface... I guess my example out there was oversimplified...

[Joffrey]

I guess there must be something else going on, because even when I complicate things a bit more to do what you describe, I still get the correct output: https://pl.kotl.in/LYzJ3k3Vy

[Joffrey]

Could you share some code that reproduces the problem you're seeing?

[dave08]

Something like this (not working, but I need to rush out now...): https://play.kotlinlang.org/#eyJ2ZXJzaW9uIjoiMS40LjAiLCJjb2RlIjoiaW50ZXJmYWNlIEJhc2VSZX[…]AgIH1cbiAgIFxufSIsInBsYXRmb3JtIjoiamF2YSIsImFyZ3MiOiIifQ==

[Joffrey]

I fixed the compile errors in your example (which is close to my last example), and it still does work fine:
https://pl.kotl.in/3noHQTl-1

[dave08]

Oh... It was the logger library printing that 🙃, I guess I was expecting that it should give me the use case's name which is a different problem... I guess that's what happens when one is overworked... Thanks for pointing this out!

Side point, do I need kotlin reflection library to use simpleName like that? Is it better to use class.java?

[Joffrey]

I'm glad you figured it out 🙂 I believe you don't need kotlin-reflect for simpleName.