Methods

Our object has no methods.  It can only be used as a hash reference.  This is bad since it breaks the object abstraction, leaking the implementation all over the caller.

We need to write some methods to provide access to the foo and bar data members without forcing the caller to use hash semantics.  These methods are called "accessors."

Accessors can be used to read data members (getters), write data members (setters), or both.