Accept everything that has a toString() method

Support
1

Is there a built-in interface that I can use to accept everything that has a toString() method?

In other words, how to change the signature of acceptsStringables() to make it work?

fun acceptsStringables(text: String) {
    println(text.toString())
}

class Foo {
    override fun toString(): String { return "hello world" }
}

fun main() {
    acceptsStringables(Foo())
}
2

Yes, it’s… Any. In Java/Kotlin all objects have the toString() method. In Java primitives don’t have it, but Kotlin tries to unify primitives and objects, so even integers, etc. have it.

3 Likes
3

Just take the string then. It’s clear you’re not doing anything else with this object.

(In case you might need the string, then you could take a lambda returning the string)

4

That is correct, but I want users of my function to be able to call it like acceptsStringables(foo) instead of acceptsStringables(foo.toString()).

5 
fun acceptsStringables(obj: Any) {
    println(obj.toString())
}

class Foo {
    override fun toString(): String { return "hello world" }
}

fun main() {
    acceptsStringables(Foo())
}