Extend data class in Kotlin

Question

Data classes seem to be the replacement to the old-fashioned POJOs in Java. It is quite expectable that these classes would allow for inheritance, but I can see no convenien

Answer 1

Declare properties in super-class outside of constructor as abstract, and override them in sub-class.

abstract class Resource {
    abstract var id: Long
    abstract var location: String
}

data class Book (
    override var id: Long = 0,
    override var location: String = "",
    var isbn: String
) : Resource()