An example of Abstract Class with Pure Virtual function?

Could you please help me out on working with abstract classes by sending me a simple example of it.


Please also write the main.cpp

An example of Abstract Class with Pure Virtual function?
Here's an example, using an abstract class Shape with a pure virtual function getArea, and two subclasses, Circle and Rectangle. Hope it helps.





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#include %26lt;iostream%26gt;





using namespace std;





class Shape {


public:


// getArea is a pure virtual method: no implementation


// is provided in the base class, which makes the base


// class abstract


virtual double getArea() = 0;


};





class Rectangle : public Shape {


public:


Rectangle(double h, double w);


virtual double getArea();


private:


double _h, _w;


};





class Circle : public Shape {


public:


Circle(double r);


virtual double getArea();


private:


double _r;


};





Rectangle::Rectangle(double h, double w) {


_h = h;


_w = w;


}





Circle::Circle(double r) {


_r = r;


}





double Rectangle::getArea() {


return _h * _w;


}





double Circle::getArea() {


return _r * _r * 3.142;


}





int main(int argc, char** argv) {


Shape* s1 = new Circle(2.0);


Shape* s2 = new Rectangle(3.0, 4.0);





cout %26lt;%26lt; "s1 area: " %26lt;%26lt; s1-%26gt;getArea() %26lt;%26lt; endl;


cout %26lt;%26lt; "s2 area: " %26lt;%26lt; s2-%26gt;getArea() %26lt;%26lt; endl;





delete s1;


delete s2;


}