Question

Kindly write the code in C++ and also please show the screenshot of the output.

Will appreciate your kind response. Thank you.

Question 2: Code this UML using pure virtual function. Shape polymorphic operations draw(g: Graphics ) getArea(): int getBoundingArea(): int abstract superclass 1 Square Circle drawl g: Graphics ) getArea(): int drawl g: Graphics ) getArea(): int concrete subclasses

Answer 1

Since its not mentioned here so I am assuming that g is an object if Graphics class which is coming as an input parameter in draw(g:Graphics) function. Therefore I am taking Graphics as a dummy empty class below. Change it as per your business logic.

In UML, if function name and class names are written in italics that means they are abstract. So here we have 2 pure virtual functions:-

1) draw(g:Graphics) -> Assuming the return type as void

2) getArea() : int

whose defintion will be provided by the concrete sub-classes Square and Circle.

Since Shape is an abstract class, we cannot instantiate its object.

Please find below in red an outline of the C++ code as per the given UML Diagram:-

You can fill up the business logic inside the functions as per your requirements.

#include <iostream>

class Graphics
{
//dummy class
};

class Shape
{
public:
Shape() = default; // Default constructor
virtual ~Shape() = default; // default virtual destructor
virtual void draw(Graphics g) = 0; // pure virtual function
virtual int getArea() = 0; // pure virtual function
int getBoundingArea();
};

int Shape::getBoundingArea()
{
std::cout << "Inside Shape::getBoundingArea();\n";
// TO-DO: fill up your business logic here
return 0;
}

class Square : public Shape {
public:
Square() = default;
virtual ~Square() = default; // Keeping virtual destructor in case of sub classing .
// If sub classing is not to be done then can be normal destructor
void draw(Graphics g) override; // This means it is overriding the base class function
int getArea() override; // Overriding base class function
};

void Square::draw(Graphics g)
{
std::cout << "Square::draw() -> Drawing Square shape\n";
// TO-DO: fill up your business logic here
}

int Square::getArea()
{
std::cout << "Square::getArea() -> Getting area of Square shape\n";
// TO-DO: fill up your business logic here
return 0;
}

class Circle : public Shape {
public:
Circle() = default;
virtual ~Circle() = default; // Keeping virtual destructor in case of sub classing .
// If sub classing is not to be done then can be normal destructor
void draw(Graphics g) override; // This means it is overriding the base class function
int getArea() override; // Overriding base class function
};

void Circle::draw(Graphics g)
{
std::cout << "Circle::draw() -> Drawing Circle shape\n";
// TO-DO: fill up your business logic here
}

int Circle::getArea()
{
std::cout << "Circle::getArea() -> Getting area of Circle shape\n";
// TO-DO: fill up your business logic here
return 0;
}

int main()
{
Graphics g; // Dummy Graphics class object
Shape *square = new Square(); // Creating Square class object of base class type i.e Shape
square->draw(g); // It will call Square::draw() since its overridden by subclass Square
square->getArea(); // It will call Square::getArea() since its overridden by subclass Square
square->getBoundingArea(); // It will call Shape::getBoundingArea() since its not overridden by subclass Square
  
Shape *circle = new Circle(); // Creating Circle class object of base class type i.e Shape
circle->draw(g); // It will call Circle::draw() since its overridden by subclass Circle
circle->getArea(); // It will call Circle::getArea() since its overridden by subclass Circle
circle->getBoundingArea(); // It will call Shape::getBoundingArea() since its not overridden by subclass Circle
  
delete(square); // Deleting square object
delete(circle); // Deleting circle object

return 0;
}

Output:-

Square::draw() -> Drawing Square shape                                                                                                          

Square::getArea() -> Getting area of Square shape                                                                                               

Inside Shape::getBoundingArea();                                                                                                                

Circle::draw() -> Drawing Circle shape                                                                                                          

Circle::getArea() -> Getting area of Circle shape                                                                                               

Inside Shape::getBoundingArea();   

...Program finished with exit code 0                                                                                                            

Press ENTER to exit console.   

As you can see in the main function, we have used the Pointer of Base class type i.e. Shape which is referring to the subclass Square/Circle. This is the functionality of virtual functions in C++.

Code will be compiled on C++11 or above since override keyword has been introduced in C++11.

For your reference, please find below the screenshots for the code as well as of the output screen.

CODE:-

#include <iostream> class Graphics { //dummy class }; class Shape { public: Shape() = default; // Default constructor virtual Shape() = default; // default virtual destructor virtual void draw(Graphics g) 0; // pure virtual function virtual int getArea() = 0; // pure virtual function int getBoundingArea(); }; int Shape::getBoundingArea() { std::cout << "Inside Shape::getBoundingArea();\n"; // TO-DO: fill up your business Logic here return; } class Square : public Shape { public: Square() = default; virtual Square() = default; // Keeping virtual destructor in case of sub classing - // If sub classing is not to be done then can be normal destructor void draw(Graphics g) override; // This means it is overriding the base class function int getArea() override; // Overriding base class function };

void Square:: draw(Graphics g) { std::cout << "Square::draw() -> Drawing Square shape\n"; // TO-DO: fill up your business Logic here نہا int Square::getArea) { std::cout << "Square::getArea() -> Getting area of Square shape\n"; // TO-DO: fill up your business Logic here return; مہ class Circle : public Shape { public: Circle() = default; virtual Circle() = default; // Keeping virtual destructor in case of sub classing . // If sub classing is not to be done then can be normal destructor void draw(Graphics g) override; // This means it is overriding the base class function int getArea() override; // Overriding base class function }; void Circle::draw(Graphics g) { std::cout << "Circle::draw() -> Drawing Circle shape\n"; // TO-DO: fill up your business Logic here }

{ int Circle::getArea() std::cout << "Circle::getArea() -> Getting area of Circle shape\n"; // TO-DO: fill up your business Logic here return 0; بہ int main() { Graphics g; // Dummy Graphics class object Shape *square new Square(); // Creating Square class object of base class type i.e Shape square->draw(g); // It will call Square::draw() since its overridden by subclass Square square->getArea(); // It will call Square::getArea() since its overridden by subclass Square square->getBoundingArea(); // It will call Shape::getBoundingArea() since its not overridden by subclass Square Shape *circle new Circle(); // Creating Circle class object of base class type i.e Shape circle->draw(g); // It will call Circle::draw() since its overridden by subclass Circle circle->getArea(); // It will call Circle::getArea() since its overridden by subclass Circle circle->getBoundingArea(); // It will call Shape::getBoundingArea() since its not overridden by subclass Circle delete( square); // Deleting square object delete(circle); // Deleting circle object return; }

OUTPUT:-

Square::draw() -> Drawing Square shape Square::getArea() -> Getting area of Square shape Inside Shape::getBoundingArea(); Circle::draw() -> Drawing Circle shape circle::getArea() -> Getting area of Circle shape Inside Shape::getBoundingArea(); ... Program finished with exit code 0 Press ENTER to exit console.]

Hope it helps!

Cheers!!