For the code below, Choose the correct statement which explains the error?

abstract class A { type B <: C abstract class C { def superClassM(b: B): D } class EImpl extends C { def superClassM(b: B): D = { val e = func1(this, b) e } } def func1(b: B, b1: B): D = D(b, b1) case class D(a: B, b: B) } When complied produces the following error found : EImpl.this.type (with underlying type A.this.EImpl) required: A.this.B val e = func1(this, b) ^

Choose the expression that allows the code to compile

Given the type hierarchy defined below, Choose correct statement below?

For the type heirachy defined below, Choose the most correct statement below for the output?

Which one is false about Futures and Promises?

Best description for the variance expression as following?

The map method on List (and Seq), transforms each element of a collection based on a function. For example, if we have a List[String] and want to convert it to all lowercase?

Statement that is not correct for Scala's mutable.Map?

Choose correct output using the code?

How to groupBy using multiple columns in Scala collections?

Output of following code?