Hello, World! Is there any documentation somewhere about how

equals

work for sealed classes?

It works exactly the same as everywhere else.

it’s not completely obvious for me 🙂 In my case I have a sealed class with 2 possible values: one object, and one data class. In case I compare 2 instances of the data class, will the equals of the data class be called?

Yes, the call

equals

is a call to a polymorphic function. The exact function to call (

equals

in

Any

or

equals

in your data class, etc.) is determined at runtime based on the actual type of the object.

oh so by default the

equals

of the “sub type” is used. Makes sense. What if I override the

equals

of the sealed class however?

It's a normal polymorphic method call. The method "furthest down" in the inheritance chain will be called. If you have:

A extends B extends C

and only

B

has

equals

then objects of type

C

will use that equals.

all right it makes sense 🙂 Thanks a lot!