why do i get `java.lang.ClassFormatError: Duplicat...

# announcements

[Smallville7123]

why do i get java.lang.ClassFormatError: Duplicate method name&signature in class file FileKt in https://pl.kotl.in/tLfGFlvku

[Ruckus]

Because String.toStringBuilder() and Sting?.toStringBuilder() have the same signature.

[Smallville7123]

so that ONLY compiles in kotlin/native?

[Ruckus]

Yes, sorry. They have the same signature on the JVM, which is what you are running on in the playground.

[Smallville7123]

;-;

[Ruckus]

To fix it on the JVM, you can use something like

@JvmName("toStringBuilderOrNull")
fun String?.toStringBuilder()...

[Smallville7123]

ok o.o

[Ruckus]

Or honestly don't define that function.

[Ruckus]

That way at the use site, if you're using a nullable string, you have to specify

myString?.toStringBuilder()

and the usage makes it clear what the expected result is.

[Smallville7123]

ok

[Ruckus]

Considering your definition can be rewritten as

fun String?.toStringBuilder() = this?.toStringBuilder()

you might as well just use it that way. No reason to define an extra function to save 1 character.

[Ruckus]

But that's just my opinion.

[Smallville7123]

ok

[Smallville7123]

i like having the function directly accessible in auto-completion without needing to put ? to access it lol