Hands-On Object-Oriented Programming with Kotlin

Companion objects

Other programming languages, including Java and C#, allow us to use static variables and static functions. We can declare functions as static when they are utility functions that should be accessible without having to create a class object. Kotlin, however, does not provide a static keyword for a variable or a function. Instead, it allows us to add a companion object inside the class to declare a static function or variable.

Let's take a look at how to declare a companion object.

Create a normal class called Parent. Within the class body, declare a companion object:

class Parent {    companion object {        const val count = 10        fun companionFunction() {            println("I am your companion")        }    }    fun getCompanions(){ companionFunction() ...