How to call extension function of the base class in a derived class using the super keyword?
I tried to call using super but it doesn't work.
open class abc {
open fun aa() {
println("function in abc")
}
}
fun abc.sum() {
println("extension function")
}
class ab: abc() {
override fun aa() {
super.aa()
println("functon in ab")
}
fun sum() {
super.sum()
println("sum function")
}
}
fun main(args: Array < String > ) {
var aa: ab = ab()
aa.aa()
aa.aa()
aa.sum()
}
Here is the 16th number line error comes, I can't call the extension function.
As you created the extension out of the class it is no more member of that class. You are able to call
super.aa()
as it is the member of theabc
class.In order to use that method you have to call it in following way.
For more info refer this link
This will do:
super
does not work as extension functions are not members of the base class to be overridden in derived classes.This type of namespace conflict is a general drawback of extension methods. Extension methods are essentially static and do not mix well with inheritance.
In your particular case, there doesn't seem to be a need for the function
sum
to be an extension method. If you change it to anopen
virtual method, you will be able to design better for inheritance and potential overriding in a subclass.