On the basis of deep analyzing the kinds of data members of class in c++ language, and discussing about the effect and realization methods of data member initialization ,and after pointing out the problem in programming design and giving out the resolvent, the author gives the examples to show the methods of initializing data members using constructor function.

According to the analysis of characteristics of curve layout data, the class design program of curve layout is introduced with object_oriented paradigm, including the partition of hierarchy of classes and the design of data members and member functions for each class.