First class program, how to implement design ideas?

[nostromo]

I'm now learning about classes, and after doing this exercise, which has one class using another class, I thought I would build the program up with more options.

Here is the initial exercise:

// Pizza-using-Circle-class.cpp
// date: Sun Mar 20 2016
// Create a Pizza class that uses a Circle class.
#include <iostream>
#include <cmath>    // in order to use pow(x, 2) function
using namespace std;

class Circle
{
private:
    double radius;

public:
    void setRadius(double r)
    { radius = r; }
    double getArea()
    { return 3.14 * pow(radius, 2); }
};

class Pizza
{
private:
    double price;
    string type;
    Circle size;

public:
    void setName(string t)
    { type = t; }
    string getName()
    { return type; }
    void setPrice(double p)
    { price = p; }
    void setSize(double r)
    { size.setRadius(r); }
    double costPerSqin()
    { return (price + size.getArea()); }
};

int main()
{

    Pizza myPizza;
    myPizza.setPrice(0.99);
    myPizza.setSize(2.5);
    cout << endl << "Price per square inch $" << myPizza.costPerSqin();
    cout << endl;
	return 0;
}

Here is the output:

Price per square inch $20.615

From there I built up this program, which I later separated into 5 files, and got those working as well:

// Pizza-using-Circle-class-menu-if-stmt.cpp
// date: Sun Mar 20 2016
// Create a Pizza class that uses a Circle class.
// MOD: build up this program using function prototypes and place
//       functions outside the class.  Add a menu and user select items.

#include <iostream>
#include <cmath>                    // in order to use pow(x, 2)
#include <iomanip>                  // in order to set dollar .00 placement
using namespace std;

// Circle class declaration
class Circle
{
private:
    double radius;

public:
    Circle();                   // Constructor prototype
    ~Circle();                  // Destructor prototype
    void setRadius(double r);
    double getArea();
}; // end Circle class

class Pizza
{
private:
    double price;
    string type;
    Circle size;

public:
    Pizza();                        // Constructor prototype
    ~Pizza();                       // Destructor prototype
    void setName(string t);
    string getName();
    void setPrice(double p);
    void setSize(double r);
    double costPerSqin();
}; // end Pizza class

Circle::Circle()
{
    radius = 0.0;
}

Circle::~Circle()
{
    ;
}

void Circle::setRadius(double r)
{
    radius = r;
}

double Circle::getArea()
{
    return 3.14 * pow(radius, 2);
}

Pizza::Pizza()
{
    price = 0.0;
    type = "";
}

Pizza::~Pizza()
{
    ;
}

void Pizza::setName(string t)
{
    type = t;
}

string Pizza::getName()
{
    return type;
}

void Pizza::setPrice(double p)
{
    price = p;
}

void Pizza::setSize(double r)
{
    size.setRadius(r);
}

double Pizza::costPerSqin()
{
    return (price + size.getArea());
}

int main()
{
    string pizzaName    = "";
    double smallSize    = 3.0;  // slice wide end size = 3"
    double smallPrice   = 1.99; // price per slice
    double mediumSize   = 3.25;
    double mediumPrice  = 2.50;
    double largeSize    = 3.5;
    double largePrice   = 2.99;
    double xLargeSize   = 4.0;
    double xLargePrice  = 3.99;
    double xxLargeSize  = 4.5;
    double xxLargePrice = 4.99;

    Pizza newPizza;             // instantiate newPizza from Pizza class

    cout << endl;
    cout << "What size pizza do you want: " << endl;
    cout << endl;
    cout << "small"   << endl;
    cout << "medium"  << endl;
    cout << "large"   << endl;
    cout << "xlarge"  << endl;
    cout << "xxlarge" << endl;
    cout << endl;
    cout << "enter:  ";
    cin >> pizzaName;

    if (pizzaName == "small")
    {
        newPizza.setName(pizzaName);
        newPizza.setPrice(smallSize);
        newPizza.setSize(smallPrice);
    }
    else if (pizzaName == "medium")
    {
        newPizza.setName(pizzaName);
        newPizza.setPrice(mediumSize);
        newPizza.setSize(mediumPrice);
    }
    else if (pizzaName == "large")
    {
        newPizza.setName(pizzaName);
        newPizza.setPrice(largeSize);
        newPizza.setSize(largePrice);
    }
    else if (pizzaName == "xlarge")
    {
        newPizza.setName(pizzaName);
        newPizza.setPrice(xLargeSize);
        newPizza.setSize(xLargePrice);
    }
    else if (pizzaName == "xxlarge")
    {
        newPizza.setName(pizzaName);
        newPizza.setPrice(xxLargeSize);
        newPizza.setSize(xxLargePrice);
    }
    else
    {
        cout << endl << "ERROR!! " << pizzaName << " is not a valid entry.  Exiting program." << endl;
        return 1;
    } // end if

    cout << endl;
    cout << fixed << showpoint << setprecision(2) << endl;
    cout << "You ordered a " << newPizza.getName() << " pizza which will cost you $"
         << newPizza.costPerSqin() << "." << endl;
    cout << endl;
	return 0;
}

What size pizza do you want:

small
medium
large
xlarge
xxlarge

enter:  small

You ordered a small pizza which will cost you $15.43.

[nostromo]

Now, I thought it might be a good idea that instead of outlining all these variables separately, that I'd look at arrays. So I built a separate program to test that:

// MOD2: place the pizza size names, slice sizes and cost in 3 arrays.
#include <iostream>
#include <iomanip>
using namespace std;

void setArray(string pizzaName[], double sliceSize[], double slicePrice[], int size);
void getChoice(string pizzaName[], double slicePrice[]);

int main()
{
    const int NUM_SIZE = 5;
    string pizzaName[NUM_SIZE]  = {"small", "medium", "large", "xlarge", "xxlarge"};
    double sliceSize[NUM_SIZE]  = {3.0, 3.25, 3.5, 4.0, 4.5};
    double slicePrice[NUM_SIZE] = {1.99, 2.50, 2.99, 3.99, 4.99};

    setArray(pizzaName, sliceSize, slicePrice, NUM_SIZE);
    getChoice(pizzaName, slicePrice);

    return 0;
}

void setArray(string pizzaName[], double sliceSize[], double slicePrice[], int size)
{
    for (int count = 0; count < size; count++)
        cout << setw(7) << left << "Choice: "
             << setw(7) << pizzaName[count] << " - "
             << setw(4) << sliceSize[count] << " - "
             << setw(7) << slicePrice[count] << endl;
    cout << endl;
}

void getChoice(string pizzaName[], double slicePrice[])
{
    // initialize choice variable for user input
    int choice = 0;

    cout << "Enter choice number for the size of the pizza you want:" << endl;
    cout << endl;
    cout << "small   - 1: " << endl;
    cout << "medium  - 2: " << endl;
    cout << "large   - 3: " << endl;
    cout << "xlarge  - 4: " << endl;
    cout << "xxlarge - 5: " << endl;
    cout << endl << " >> ";
    cin >> choice;

switch(choice)
{
        case 1:     cout << fixed << showpoint << setprecision(2) << endl;
                    cout << "You ordered a " << pizzaName[choice-1] << " pizza which will cost you $"
                         << slicePrice[choice-1] << "." << endl;
                    break;
        case 2:     cout << fixed << showpoint << setprecision(2) << endl;
                    cout << "You ordered a " << pizzaName[choice-1] << " pizza which will cost you $"
                         << slicePrice[choice-1] << "." << endl;
                    break;
        case 3:     cout << fixed << showpoint << setprecision(2) << endl;
                    cout << "You ordered a " << pizzaName[choice-1] << " pizza which will cost you $"
                         << slicePrice[choice-1] << "." << endl;
                    break;
        case 4:     cout << fixed << showpoint << setprecision(2) << endl;
                    cout << "You ordered a " << pizzaName[choice-1] << " pizza which will cost you $"
                         << slicePrice[choice-1] << "." << endl;
                    break;
        case 5:     cout << fixed << showpoint << setprecision(2) << endl;
                    cout << "You ordered a " << pizzaName[choice-1] << " pizza which will cost you $"
                         << slicePrice[choice-1] << "." << endl;
                    break;
        default:    cout << endl << "ERROR!! " << pizzaName[choice-1] 
                     << " is not a valid entry.  Exiting program." << endl;
    }
}

What I don't know how to do at this point is figure out how to combine this last program with arrays into the Pizza-Circle class to make it work like objects. I even thought today I could build it using a struct:

// MOD 3: using a struct.

#include <iostream>
#include <iomanip>
using namespace std;

const int ARRAY_SIZE = 5;

struct Pizza
{
	string name[ARRAY_SIZE];
	double sliceSize[ARRAY_SIZE];
	double slicePrice[ARRAY_SIZE];
};

int main()
{
	Pizza order;

	order = { {"small", 3.00, 1.99},
              	  {"medium", 3.50, 2.50},
                  {"large", 4.00, 2.99},
                  {"xlarge", 4.50, 3.99},
                  {"xxlarge", 5.00, 4.99} };

    cout << endl;
    cout << order << endl;

    cout << endl;
    return 0;
}

But it doesn't work, and I don't know how to build it out as a struct or array to combine it with the Pizza-Circle class. Any suggestions would be welcome, or other design ideas that would work more efficiently.