Type from Scala reflection

Question

Suppose that I have:

trait A

class B extends A

compiled into class files. Later I load those using reflection:

val a = Class forName "A"
val b = Class forName "B"

Could anyone tell me how to check whether b is the subtype of a?

Answer 1

Use the isAssignableFrom method in Class:

a isAssignableFrom b

This returns true if b is a subclass/subinterface of a or b == a.

Answer 2

You can just call the getInterfaces method on b and iterate through the array to see if any of them equals a.