Companion objects are declared within a class by utilizing the companion and object keywords. You can use functions that are static within a companion object:
class Printer { companion object DocumentPrinter { fun printDocument() = println("Document printing successful.") }}fun main(args: Array<String>) { Printer.printDocument() // printDocument() invoked via companion object Printer.Companion.printDocument() // also invokes printDocument() via // a companion object}
Sometimes, you may want to give an identifier to a companion object. This can be done by placing the name after the object keyword. Consider the following example:
class Printer { companion object DocumentPrinter { // Companion object identified by DocumentPrinter ...
