C++ Multilevel inheritance / polymorphism - c++

Question

I'm currently working on my C++ assignment and I'm working through polymorphism and I keep getting error messages. Would appreciate any help. Thanks in advance!
The assignment uses a shape inheritance hierarchy that looks like this:
Circle
Two Dimensional Shape
Cylnder
Shape
Three Dimensional Shape
Below is the error messages I'm getting.
1>Circle.obj : error LNK2019: unresolved external symbol "public: __thiscall TwoDimensionalShapes::TwoDimensionalShapes(void)" (??0TwoDimensionalShapes##QAE#XZ) referenced in function "public: __thiscall Circle::Circle(void)" (??0Circle##QAE#XZ)
1>Cylinder.obj : error LNK2019: unresolved external symbol "public: __thiscall ThreeDimensionalShapes::ThreeDimensionalShapes(void)" (??0ThreeDimensionalShapes##QAE#XZ) referenced in function "public: __thiscall Cylinder::Cylinder(void)" (??0Cylinder##QAE#XZ)
I'm pretty much done with my program but I'm not sure where the problems are coming from.
Here's my source code:
#include "Cylinder.h"
#include "Circle.h"
#include <iostream>
#include <iomanip>
using namespace std;
int main()
{
// next line commented out because will now cause compile error
// Shape shpeObj; // instantiate a Shape object
cout << "The Shape object count is: " << Shape::getObjectCount() << '\n';
Circle crclObj; // instantiate a Circle object
Cylinder cyldObj; // instantiate a Cylinder object
// Count will be 2 in statement below because a Shape object is contained
// within each Circle and Cylinder object.
cout << "The Shape object count is: " << Shape::getObjectCount() << "\n";
Shape * shpePtr = &cyldObj; // declare a Shape pointer
// and have it point to the Cylinder object
Shape & shpeRef = cyldObj; // declare a Shape reference
// and have it reference the Cylinder object
// The above 2 statments are ok because a derived class object IsA base class object!
// No additional objects created, so the count is still the same.
cout << "The Shape object count is: " << Shape::getObjectCount() << "\n";
// Dynamically create 2 objects
Shape * shpePtr2 = new Circle;
Shape & shpeRef2 = *new Cylinder;
// The count should now be 4
cout << "The Shape object count is: " << Shape::getObjectCount() << "\n";
// Now destroy the 2 dynamically created objects!
delete shpePtr2;
delete &shpeRef2;
//The count should now be 2 again.
cout << "The Shape object count is: " << Shape::getObjectCount() << "\n\n";
/* Can no longer test Shape class, since it is now an Abstract Base Class (ABC)
// Test Shape class
shpeObj.setNoOfSides(0);
cout << "The number of sides is: " << shpeObj.getNoOfSides() << "\n\n";
cout << "The area of shpeObj is: " << shpeObj.Area() << '\n';
cout << "The volume of shpeObj is: " << shpeObj.Volume() << "\n\n\n";
*/
// Test Circle class
crclObj.setRadius(3.0);
cout << fixed << setprecision(4); // force use of decimal point and 4 digits of
// precision after the decimal place
cout << "The radius of crclObj is: " << crclObj.getRadius() << "\n\n";
cout << "The number of sides is: " << crclObj.getNoOfSides() << "\n\n";
cout << "The area of crclObj is: " << crclObj.Area() << '\n';
// next line no longer valid in my solution for this assignment
//cout << "The volume of crclObj is: " << crclObj.Volume() << "\n\n\n";
// Test Cylinder class
cyldObj.setRadius(5.5);
cyldObj.setHeight(2.5);
cout << "The radius of cyldObj is: " << cyldObj.getRadius() << '\n';
cout << "The height of cyldObj is: " << cyldObj.getHeight() << "\n\n";
cout << "The number of sides is: " << cyldObj.getNoOfSides() << "\n\n";
cout << "The area of cyldObj is: " << cyldObj.Area() << '\n';
cout << "The volume of cyldObj is: " << cyldObj.Volume() << "\n\n";
return 0;
}
#pragma once
class Shape
{
public:
Shape(void); //constructor
~Shape(void); //destructor
void setNoOfSides(const int &); // set the # of sides
int getNoOfSides() const; // get the # of sides
static int getObjectCount(); // get the object count
virtual double Area() const = 0; // calculate and return area
// now a pure virtual function
virtual double Volume() const; // calculate and return volume
protected:
int mNoOfSides; // represents # of sides in Shape object
static int mObjectCount; // a static member - counts the # of Shape
// objects currently instantiated
// Only one of these instantiated for the whole class!
};
#pragma once
#include "Shape.h"
class TwoDimensionalShapes :public Shape
{
public:
TwoDimensionalShapes(void); //constructor
virtual double Area() const = 0; // area of 2D shape
};
#pragma once
#include "Shape.h"
class ThreeDimensionalShapes :public Shape
{
public:
ThreeDimensionalShapes(void); // constructor
virtual double Area() const = 0; // area of 3D shape
virtual double Volume() const = 0; // volume of 3D shape
};
#pragma once
#include "TwoDimensionalShapes.h"
class Circle :public TwoDimensionalShapes
{
public:
Circle(void); // constructor
void setRadius(const double &); //set the radius
double getRadius() const; // get the radius
virtual double Area() const override; // overrides Area() method of TwoDimensionalShapes class
protected:
const static double pi; // Static member used in calculations
// Only one of these instantiated for the whole class!
double mRadius; // member used to represent radius
};
#pragma once
#include "ThreeDimensionalShapes.h"
class Cylinder :public ThreeDimensionalShapes
{
public:
Cylinder(void); // constructor
void setHeight(const double &); // set the height
double getHeight() const; // get the height
void setRadius(const double &); //set the radius
double getRadius() const; // get the radius
virtual double Area() const override; // overrides Area() method of ThreeDimensionalShapes class
virtual double Volume() const override; // overrides Volume() method of ThreeDimensionalShapes class
protected:
const static double pi; // Static member used in calculations
// Only one of these instantiated for the whole class!
double mHeight; // member used to represent height
double mRadius;
};
#include "Circle.h"
// init static data member
const double Circle::pi = 3.141592654; // init. static member
// constructor
Circle::Circle(void)
:mRadius(0.0)
{
setNoOfSides(0);
}
// used to set value for mRadius member
void Circle::setRadius(const double & setVal)
{
if (setVal > 0.0) // Make sure input is a valid value
{
this->mRadius = setVal;
}
// otherwise just leave set to original value
}
// used to return current value of mRadius member
double Circle::getRadius(void) const
{
return this->mRadius;
}
// used top calculate and return area.
double Circle::Area(void) const
{
return Circle::pi * this->mRadius * this->mRadius;
}
#include "Cylinder.h"
// init static data member
const double Cylinder::pi = 3.141592654; // init. static member
// constructor
Cylinder::Cylinder(void)
:mHeight(0.0)
{
this->setNoOfSides(3); // Why not init. this member in MIL ???
}
// used to set mHeight member
void Cylinder::setHeight(const double & setVal)
{
if (setVal > 0.0) // Make sure input is a valid value
{
this->mHeight = setVal;
}
// otherwise just leave set to original value
}
// used to return current value of mHeight member
double Cylinder::getHeight(void) const
{
return this->mHeight;
}
// used to set value for mRadius member
void Cylinder::setRadius(const double & setVal)
{
if (setVal > 0.0) // Make sure input is a valid value
{
this->mRadius = setVal;
}
// otherwise just leave set to original value
}
// used to return current value of mRadius member
double Cylinder::getRadius(void) const
{
return this->mRadius;
}
// used to caluclate and return area
double Cylinder::Area(void) const
{
double TwoPiR = 2.0 * Cylinder::pi * this->mRadius;
return (TwoPiR * this->mRadius) + (TwoPiR * this->mHeight);
}
// used to claculate and return volume
double Cylinder::Volume(void) const
{
return Cylinder::pi * this->mRadius * this->mRadius * this->mHeight;
}
#include "Shape.h"
// init static data memeber
int Shape::mObjectCount = 0;
// constructor
Shape::Shape(void)
:mNoOfSides(1)
{
++Shape::mObjectCount;
}
// desstructor
Shape::~Shape(void)
{
--Shape::mObjectCount;
}
// used to set mNoOfSides member
void Shape::setNoOfSides(const int & setVal)
{
if (setVal > 0)
{
this->mNoOfSides = setVal;
}
// otherwise just leave set to original value
}
// used to return current value of mNoOfSides member
int Shape::getNoOfSides() const
{
return this->mNoOfSides;
}
// used to return current value of mObjectCount static member
int Shape::getObjectCount()
{
return Shape::mObjectCount;
}
/* no longer required to be implemented now that it is a
pure virtual function
// used to calculate and return area
double Shape::Area(void) const
{
return 0.0;
}
*/
// used to calculate and return volume
double Shape::Volume(void) const
{
return 0.0;
}

Answer 1

OK I figured it out now. I forgot to provide a constructor implementation for my TwoDimensionalShapes and ThreeDimensionalShapes classes. Silly mistake.