Mastering Kotlin

Calling Kotlin functions from Java

Now let's look at how you might use helper functions written in Kotlin from your Java code base. The following snippet shows a top-level function, logMessage. This function is defined in a file named Logger.kt:

// top-level function in Logger.ktfun logMessage(message: String) = println(message)

Now let's see how that top-level function is called from Java:

public class KotlinFromJava {    public static void main(String[] args) {        Developer developer = new Developer("Your Name", "Kotlin");        String name = developer.getName();                LoggerKt.logMessage(name);    }}

When called from Java, the top-level function cannot be invoked as a standalone function like in Kotlin. In that case, it must call the function as a static ...