Classes,
Objects, and Interfaces
In the C++
programming language, a class consists of properties (or member
data) and methods (or member functions). The properties are data
elements, such as those contained in a structure. The methods are used for a
variety of purposes, such as initialization, assignment, operations, and data
access. You use a class declaration in the same way that you use a structure
declaration. Memory is allocated for a class when you define a class object.
Each class object has a data area for its properties and a table of pointers to
the methods it supports.
In OLE, an
object consists of data and methods, as it does in C++. However, an OLE object
adheres to stricter rules. The data is strictly internal. An object only
exposes interfaces. An interface is a set of related methods for an
object. Each object can support multiple interfaces. All OLE interfaces support
the IUnknown