Kotlin Companion Object - devrath/KotlinAlchemy GitHub Wiki

• Companion object is similar to object and the member variables and the member functions of it can be accessed in the class where it is contained.
• Companion object doesn't have a name, If a name is given to it then the caller class has to access it via its name.
• Any caller can access the member variables and their functions of it without creating the instance of the outer class.
• This pattern is useful when we want to expose some static behavior to the outside world where the creation of an instance is not needed.

Class SomeClass {
   Companion Object {
      private var count : Int = 0
      fun appendCount(){
          count++
      }
   }
}