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Inheritance Problem: BaseCall Item, Derived Class Book
Item Class
% cat item.h
class Item
{
protected:
string title;
double price;
int invent;
public:
Item();
Item(string t, double p, int i);
int getInvent();
void setInvent(int i);
void invoice(ostream &out);
};
% cat item.cpp
#include<iostream>
using namespace std;
#include<fstream>
#include "item.h"
Item::Item() : title("item"), price(0.0), invent(0) {}
Item::Item(string t, double p, int i): title(t), price(p),
invent(i) {}
int Item::getInvent()
{
return invent;
}
void Item::setInvent(int i)
{
invent = i;
}
void Item::invoice(ostream & out)
{
out.setf(ios::fixed | ios::showpoint);
out.precision(2);
out << "Item = " << title << "\nPrice = $"
<< price << endl;
}
Book Class
% cat book.h
#ifndef BOOK_H
#define BOOK_H
class Book : public Item
{
protected:
string author;
int year;
public:
Book();
Book(string t, double p, int i,
string a, int y);
void invoice( ostream &out )
const;
};
#endif
% cat book.cpp
#include<iostream>
using namespace std;
#include "item.h"
#include "book.h"
Book::Book() : Item(), author("author"), year(1900)
{}
Book:: Book(string t, double p, int i, string a, int
y) :
Item(t, p, i), author(a), year(y) {}
void Book::invoice( ostream &out) const
{
out.setf(ios::fixed | ios::showpoint);
out.precision(2);
out << "Item: " << title
<< "\nAuthor: "
<< author
<<
"\nPublished: " << year
<< "\nPrice =
$" << price << endl;
}
Driver Program
% cat book_list.cpp
#include<iostream>
using namespace std;
#include<fstream>
#include<list>
#include "item.h"
#include "book.h"
void reorder( list<Book> & BL );
int main()
{
Book b1("Advanced C++", 125.50, 42, "John B. Good", 2008);
Book b2("Computers and You", 1200.00, 1, "Ada Lovelace",1843);
Book b3("All Who Wander", 28.95, 3, "Bilbo Baggins", 1937);
Book b4("Learn to Love Exams", 9.95, 987, "P. L. Ato",
2008);
// populate a list
list<Book> bookList;
bookList.push_back( b1);
bookList.push_back( b2);
bookList.push_back( b3);
bookList.push_back( b4);
// display the list
list<Book>::iterator bit;
for(bit = bookList.begin(); bit != bookList.end(); bit++)
{
(*bit).invoice(cout);
cout << endl;
}
// insert a new book
cout << "INSERT A BOOK\n\n";
Book b5("Money Isn't Everything", 150.00, 9, "D. Trump", 2006);
bookList.insert(bit, b5);
for(bit = bookList.begin(); bit != bookList.end(); bit++)
{
(*bit).invoice(cout);
cout << endl;
}
// check inventory to reorder books
reorder( bookList );
return 0;
}
void reorder( list<Book> & BL )
{
list<Book>::iterator bit;
cout << "REORDER THESE BOOKS\n\n";
for(bit = BL.begin(); bit != BL.end(); bit++)
{ if( bit->getInvent() < 10)
{
(*bit).invoice(cout);
cout << "Inventory = "
<< bit->getInvent() << endl;
cout << endl;
}
}
}
Execution
% g++ book_list.cpp item.cpp book.cpp
% a.out
Item: Advanced C++
Author: John B. Good
Published: 2008
Price = $125.50
Item: Computers and You
Author: Ada Lovelace
Published: 1843
Price = $1200.00
Item: All Who Wander
Author: Bilbo Baggins
Published: 1937
Price = $28.95
Item: Learn to Love Exams
Author: P. L. Ato
Published: 2008
Price = $9.95
INSERT A BOOK
Item: Advanced C++
Author: John B. Good
Published: 2008
Price = $125.50
Item: Computers and You
Author: Ada Lovelace
Published: 1843
Price = $1200.00
Item: All Who Wander
Author: Bilbo Baggins
Published: 1937
Price = $28.95
Item: Learn to Love Exams
Author: P. L. Ato
Published: 2008
Price = $9.95
Item: Money Isn't Everything
Author: D. Trump
Published: 2006
Price = $150.00
REORDER THESE BOOKS
Item: Computers and You
Author: Ada Lovelace
Published: 1843
Price = $1200.00
Inventory = 1
Item: All Who Wander
Author: Bilbo Baggins
Published: 1937
Price = $28.95
Inventory = 3
Item: Money Isn't Everything
Author: D. Trump
Published: 2006
Price = $150.00
Inventory = 9
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