How to iterate through a Map[B,Int] in Scala

Question

I have a Map[B,Int] that I am trying to iterate over: So I do something like:

map foreach { case (k,v) => println(k + " " + v)}

However I keep getting the error that there is a type mismatch: Found: Unit Expected: B

I have read several times on different tutorials that traversing a map is always the same regardless of what type is point to another.

I am not sure how to fix this.

Answer 1

You need to override the toString method, otherwise print won't work. This is done by default for Int or String so that's why it complains only for B class.