Just call `hashcode()`? Can you give an example?

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[karelpeeters]

Just call hashcode()? Can you give an example?

[liminal]

that prints a 1 or 2 or 3 digit number depending on what's inside MyClass.

[liminal]

tried hashCode() or javaClass.hashCode(). the latter is always the same and is based off an interface looks like

[karelpeeters]

interface Foo {
    fun printHashcode() { println("Hash: ${hashCode()}") }
}

class Bar: Foo

fun main() {
    val bar = Bar()
    bar.printHashcode()
}

[karelpeeters]

is this not what you want?

[liminal]

I have something like this: interface MyInterface {
fun myHashCode() = "${hashCode()}"
}

sealed class MyClass : MyInterface {
data class MyClass1(val itemId: String) : MyClass() {
override fun toString() = myHashCode()
}
}

[liminal]

printing an instance of MyClass1 prints a value like "1" instead of a real hash code

[karelpeeters]

The hashCode function generated by the data class probably just returns itemId.hashCode() and maybe that happens to be 1 for the string you're using?

[liminal]

looks like the former

[liminal]

so the question still stands about being able to actually print a hashcode

[karelpeeters]

"the former"? I didn't actually say two separate things simple smile

[liminal]

1 printed is an itemId in this case

[karelpeeters]

Can you post a full runnable example?

[liminal]

interface MyInterface {
fun myHashCode() = "${hashCode()}"
}

sealed class MyClass : MyInterface {
data class MyClass1(val itemId: Int) : MyClass() {
override fun toString() = myHashCode()
}
}

fun main(args: Array<String>) {
println(MyClass.MyClass1(2))
}

[liminal]

prints 2

[karelpeeters]

itemId is an Int, not a String. The automatically generated hashcode implementation just returns that int as the hashcode.

[liminal]

i see. it's the hashCode implementation that Kotlin data class generates

[liminal]

thanks for your help @karelpeeters

[karelpeeters]

You're welcome!