CS202   4- ‹#›
Syntax of Virtual Functions
nSpecifying the keyword virtual for any base class member function enables dynamic binding for that function.
nAny derived class can override that function by defining a function with the same signature and return type.
nThe keyword virtual does not need to be re-specified within the derived class.
nOnce a member function is declared to be virtual in a base class, all functions with that name, signature, and return type in any derived class remain virtual and can be overridden.