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

Objects can implement interfaces. Inside a class, defining a simple object that doesn't implement any interfaces has no benefit in most cases. However, defining multiple objects that implement various interfaces (e.g. Comparator) can be very useful.

In terms of lifecycle, there is no difference between a companion object and a named object declared in a class.