To access internal instance variables, class implementers can use either of the following forms:
variableName
somThis->variableName
To access internal instance variables "a", "b", and "c", for example, the class implementer could use either _a, _b, and _c, or somThis->a, somThis->b, and somThis->c. These expressions can appear on either side of an assignment statement. The somThis pointer must be properly initialized in advance using the <className>GetData procedure, as shown above.
Instance variables can be accessed only within the implementation file of the class that introduces the instance variable, and not within the implementation of subclasses or within client programs. (To allow access to instance data from a subclass or from client programs, use an attribute rather than an instance variable to represent the instance data.) For C++ programmers, the _variableName form is available only if the macro VARIABLE_MACROS is defined (that is, #define VARIABLE_MACROS) in the implementation file prior to including the .xih file for the class.