CMSC 202 Computer Science II, Spring 2007, Section 010x

Lecture 17: Polymorphism

Thursday 04/05, 2007

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Assigned Reading:  15

Slides As Shown:

• Announcements, etc: [slide view] [print view]

• Virtual Member Functions : [slide view] [print view]

• Generic Sorting: [slide view] [print view]

• A Heterogeneous Linked List: [slide view] [print view]

Topics Covered:

• Recapped dynamic binding and virtual member functions.

• Used virtual member functions to design an abstract Array base class with a sorting function. Any class derived from array can be sorted using sort() without recompiling the base class functions.

  Array.h Array.cpp
  IntArray.h IntArray.cpp
  FloatArray.h FloatArray.cpp
  main1.cpp

• A hetergeneous linked list can hold different types of objects in the list at the same time. The implementation of HList brings up many issues that come up when you work with virtual functions, including:
  • the need for a virtual destructor
  • clone(): a virtual "copy constructor"
  • run-time type information
  • dynamic type casting