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CSE 20232Lecture 32 – Inheritance “Is A” vs. “Has A” class relationship Base and derived classes Protected members Types of inheritance Public, protected, private Examples: shape, point, line, square, triangle, circle Move show program Class relationships A Rolodex “has a” sequence of RoloCards as a part of it A Circle “is a” Shape with some extra or redefined attributes and functions In an “is a” relationship the derived class “inherits” all of the attributes and functions of the base class A Circle inherits everything that a Shape is, and then we add to it or redefine what we want Class Hierarchy The object oriented approach to programming encourages … Development of classes from general to specialized Using attributes and functions of base classes to create more specialized ones This hierarchy facilitates software reuse Definitions and terms Base class The class upon which another is based A Shape is a bass class of Square Derived class The class that is based upon (or derived from) another Square is a derived class, based on Shape Protected A derived class has complete access to the protected section of its base class In all other respects, protected is the same as private Types of Inheritance Public (most commonly used) The derived class has direct access to all public and protected sections of the base class Base class members have same status (public, protected, private) as part of the derived class Protected The derived class has direct access to all public and protected sections of the base class All base class members have protected status as part of the derived class Private The derived class has direct access to all public and protected sections of the base class All base class members have private status as part of the derived class A Shape class // this is a base class for all 2-d and 3-shapes all it // contains is an indication of what character it is drawn with class shape { public: Shape(char ch=‘*’) : drawChar(ch) { } void setDraw