Pros and cons of static type systems

A language is statically typed if the type of a variable is known at compile time. That is, types are checked before run time. There are pros and cons that are commonly associated with the majority of static type systems. Scala's implementation of a static type system, which is advanced, attempts to address some of the cons.

In this exercise, you'll categorize statements about static type systems as either a pro, a con, or a con that is addressed by a feature of Scala's static type system.