Multiple inheritance

Multiple inheritance

A class may inherit from more than one class by simply specifying more base classes, separated by commas, in the list of a class's base classes (i.e., after the colon). For example, if the program had a specific class to print on screen calledOutput, and we wanted our classes Rectangle and Triangle to also inherit its members in addition to those of Polygon we could write:

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class Rectangle: public Polygon, public Output; class Triangle: public Polygon, public Output;

Here is the complete example: 

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// multiple inheritance #include <iostream> using namespace std; class Polygon { protected: int width, height; public: Polygon (int a, int b) : width(a), height(b) {} }; class Output { public: static void print (int i); }; void Output::print (int i) { cout << i << '\n'; } class Rectangle: public Polygon, public Output { public: Rectangle (int a, int b) : Polygon(a,b) {} int area () { return width*height; } }; class Triangle: public Polygon, public Output { public: Triangle (int a, int b) : Polygon(a,b) {} int area () { return width*height/2; } }; int main () { Rectangle rect (4,5); Triangle trgl (4,5); rect.print (rect.area()); Triangle::print (trgl.area()); return 0; }

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