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kotlinlang

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 :slightly_smiling_face: 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 :slightly_smiling_face: Thanks a lot!