Polymorphism & Casting

Polymorphism isn’t the same as casting. When you cast a type to another, it behaves like the new type. The code that’s executed is that of the type to which it is cast, not the original type.

Let’s look at an example: Here’s a simple class hierarchy with two classes, each exposing a single member, a property called Name. The Parent class returns the String “Parent” in the get accessor, while the Child class returns the String “Child”. (We’ll examine redefining inherited members in detail in the next section.)

Public Class Parent
 Public Property Name As String
  Get
   Return "Parent"
  End Get
 End Property
End Class