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Kotlin Programming: The Big Nerd Ranch Guide, First Edition by David Greenhalgh, Josh Skeen

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Beyond Classes

Kotlin affords developers greater flexibility with respect to the format of the code that 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 the main function that you worked in before.

Listing 20.17  Declaring a top-level function in Kotlin (Hero.kt)

fun main(args: Array<String>) {
    ...
}

fun makeProclamation() = "Greetings, beast!"

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

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