Artwork Program (Inheritance)

[dub1987]

This program compiles and runs until the user inputs the media, material, or type then it crashes. Please help.

#include<iostream>
#include<string>

using namespace std;

class art
{
public:
	virtual void artID() = 0;
	virtual void artTitle() = 0;
	virtual void artist() = 0;

	virtual int getID() = 0;
	virtual string getTitle() = 0;
	virtual string getArtist() = 0;

	string title, name;
	int x;
};

class painting : public art
{
public:
	void artID()
	{
		cout << "Enter the artwork ID number.\n";
		cin >> x;
	};

	void artTitle()
	{
		cout << "Enter the artwork Title.\n";
		cin >> title;
	};

	void artist()
	{
		cout << "Enter the Artist.\n";
		cin >> name;
	};

	void media()
	{
		cout << "Enter the Media used:\n";
		cout << " Oil, Watercolor, Pastel, or Mixed-media.\n";
		cin >> me;
	};

	void height()
	{
		cout << "Enter the height:\n";
		cin >> h;
	};
	void width()
	{
		cout << "Enter the width:\n";
		cin >> w;
	};

	void show()
	{
		cout << "Painting\n";
		cout << "   ID Number: " << x << endl;
		cout << "   Title: " << title << endl;
		cout << "   Artist: " << name << endl;
		cout << "   Media: " << me << endl;
		cout << "   Dimensions: " << h << " x " << w << endl;
	};

	int getID()
	{
		return x;
	};
	string getTitle()
	{
		return title;
	};
	string getArtist()
	{
		return name;
	};
	string getMedia()
	{
		return me;
	};
	double getheight()
	{
		return h;
	};
	double getWidth()
	{
		return w;
	};

private:
	string me;
	double h, w;

	string title, name;
	int x;
};

class sculptures : public art
{
public:
	void artID()
	{
		cout << "Enter the artwork ID number.\n";
		cin >> x;
	};

	void artTitle()
	{
		cout << "Enter the artwork Title.\n";
		cin >> title;
	};

	void artist()
	{
		cout << "Enter the Artist.\n";
		cin >> name;
	};

	void material()
	{
		cout << "Enter material used:\n";
		cout << " Wood, Metal, or Plastic.\n";
		cin >> m;
	};

	void show()
	{
		cout << "Sculpture\n";
		cout << "   ID Number: " << x << endl;
		cout << "   Title: " << title << endl;
		cout << "   Artist: " << name << endl;
		cout << "   Material: " << m << endl;
	};

	string getMaterial()
	{
		return m;
	};
	int getID()
	{
		return x;
	};
	string getTitle()
	{
		return title;
	};
	string getArtist()
	{
		return name;
	};

private:
	string m;
	string title, name;
	int x;
};

class pottery : public art
{
public:
	void artID()
	{
		cout << "Enter the artwork ID number.\n";
		cin >> x;
	};

	void artTitle()
	{
		cout << "Enter the artwork Title.\n";
		cin >> title;
	};

	void artist()
	{
		cout << "Enter the Artist.\n";
		cin >> name;
	};
	void type()
	{
		cout << "Enter the Pottery Type.\n";
		cin >> t;
	};
	void height()
	{
		cout << "Enter the height:\n";
		cin >> h;
	};
	void width()
	{
		cout << "Enter the width:\n";
		cin >> w;
	};
	void show()
	{
		cout << "Pottery\n";
		cout << "   ID Number: " << x << endl;
		cout << "   Title: " << title << endl;
		cout << "   Artist: " << name << endl;
		cout << "   Type: " << t << endl;
		cout << "   Dimensions: " << h << " x " << w << endl;
	};

	string getType()
	{
		return t;
	}
	double getheight()
	{
		return h;
	};
	double getWidth()
	{
		return w;
	};
	int getID()
	{
		return x;
	};
	string getTitle()
	{
		return title;
	};
	string getArtist()
	{
		return name;
	};
private:
	double h, w;
	string t;
	string title, name;
	int x;
};

int main()
{
	int choice;

	art *artWork = NULL;
	painting *paint = NULL;
	sculptures *sculpt = NULL;
	pottery *clay = NULL;

	cout << "Which art form would you like to input information for?\n";
	cout << "      1 - Painting\n";
	cout << "      2 - Sculpture\n";
	cout << "      3 - Pottery\n";
	cin >> choice;

	if (choice == 1)
	{
		artWork = new painting();
		artWork -> artTitle();
		artWork -> artID();
		artWork -> artist();
		paint -> media();
		paint -> height();
		paint -> width();
		paint -> show();

	}
	else if (choice == 2)
	{
		artWork = new sculptures();
		artWork -> artID();
		artWork -> artTitle();
		artWork -> artist();
		sculpt -> material();
		sculpt -> show();
	}
	else if (choice == 3)
	{
		artWork = new pottery();
		artWork -> artID();
		artWork -> artTitle();
		artWork -> artist();
		clay -> height();
		clay -> width();
		clay -> show();
	}
	return 0;
}

[dub1987]

Any help would be much appreciated

[booradley60]

Lines 260-263, 272-273, and 281-283 all try to call a method using a null pointer. "paint", "sculpt", and "clay" are never set to anything.

The only objects you create are ones that are referenced with a base class (art) pointer. If you have a base class pointer, you can only exercise methods defined in the base class (unless you cast the pointer down to a derived type, which often indicates a flaw in design).

[dub1987]

So what is a suggestion for a fix for this. I thought this was fine... until it crashed.

[dub1987]

so I fixed it... here is what I I came up with:

int main()
{
	int choice;

	
	painting paint = painting();
	sculptures sculpt = sculptures();
	pottery clay = pottery();

	cout << "Which art form would you like to input information for?\n";
	cout << "      1 - Painting\n";
	cout << "      2 - Sculpture\n";
	cout << "      3 - Pottery\n";
	cin >> choice;

	if (choice == 1)
	{
		
		paint.artTitle();
		paint.artID();
		paint.artist();
		paint.media();
		paint.height();
		paint.width();
		paint.show();

	}
	else if (choice == 2)
	{
		sculpt.artID();
		sculpt.artTitle();
		sculpt.artist();
		sculpt.material();
		sculpt.show();
	}
	else if (choice == 3)
	{
		clay.artID();
		clay.artTitle();
		clay.artist();
		clay.height();
		clay.width();
		clay.show();
	}
	return 0;
}