Kotlin Programming: The Big Nerd Ranch Guide, 2nd Edition

Beyond Classes

Kotlin affords developers greater flexibility with respect to the format of the code they write. A Kotlin file can include classes, functions, and variables – all at the top level of the file. In Java, a file represents exactly one class. How, then, are top-level functions declared in Kotlin represented in Java?

Expand the interspecies communication with a proclamation from the hero. Declare a function called makeProclamation in Hero.kt outside of main.

Listing 23.17  Declaring a top-level function in Kotlin (Hero.kt)

fun main() {
    ...
}

fun makeProclamation() = "Greetings, beast!"

You will need a way to invoke this function from Java, so add a main method to Jhava.

Listing 23.18  Defining a main method ...