Data members define instance data of a class. Data Members must be defined in the main block of the class. Data members of a class are defined using the standard ABL DEFINE statements, with the addition of an optional access mode for each data member. The access mode is valid only for data member definitions in the main block of a class definition file (not for local method data, for example).
Data members in a class can specify an access mode, which tells ABL whether the data member should be visible only within the class (PRIVATE), visible to itself and other classes that inherit from it (PROTECTED), or visible to any other procedure or class in the same OpenEdge session (PUBLIC).
For more information on Object-oriented programming, see the guide OpenEdge Development: Object-oriented Programming.