Kotlin: Difference between object and companion object in a class

Question

What is the difference between an object and a companion object in a class in kotlin?

Example:

class MyClass {

    object Holder {
        //somethi         


        

Answer 1

Companion object exists because you can call companion objects' functions/properties like it is a java static method/field. And for why your Holder is allowed, well, there is no reason that declaring a nested object is illegal. It may comes in handy sometimes.