3.13 C++ Exercises and Solutions C ++ H ow to Prog ram ( 8th Ed ition ) By Paul Deitel,

Create a class called Invoice that a hardware store might use to represent an invoice for an
item sold at the store. An Invoice should include four data members—a part number (type string), a part description (type string), a quantity of the item being purchased (type int) and a price per item (type int).

[Note: In subsequent chapters, we’ll use numbers that contain decimal points (e.g., 2.75)—called floatingpoint values—to represent dollar amounts.] Your class should have a constructor that initializes the four data members. Provide a set and a get function for each data member.

In addition, provide a member function named getInvoiceAmount that calculates the invoice amount (i.e., multiplies the quantity by the price per item), then returns the amount as an int value. If the quantity is not positive, it should be set to 0. If the price per item is not positive, it should be set to 0. Write a test program that demonstrates class Invoice’s capabilities.

Solution:

Part :A

#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <Invoice.h>

using namespace std;
int main()
{
// initialization with constructor
Invoice invoice1 ("Part_123", "one paper", ‐7, 2000) ;
Invoice invoice2 ("Part_234", "long", 20, 50000) ;
// output constructor results
cout << "\nNew invoice details: \nPart Number: " << invoice1. getPartNumber()
<< "\nDescription: " << invoice1. getPartDescription()
<< "\nQuantity: " << invoice1. getQuantity()
<< "\nPrice: " << invoice1. getPrice() << endl;
cout << "\nNew invoice details: \nPart Number: " << invoice2. getPartNumber()
<< "\nDescription: " << invoice2. getPartDescription()
<< "\nQuantity: " << invoice2. getQuantity()
<< "\nPrice: " << invoice2. getPrice() << endl;
// get price and quantity by get functions
int x1 = invoice1. getQuantity() ;
int y1 = invoice1. getPrice() ;
int x2 = invoice2. getQuantity() ;
int y2 = invoice2. getPrice() ;
// calculate invoice by getInvoiceAmount function

cout << "\n1 amount is " << invoice1. getInvoiceAmount ( x1, y1 ) << endl;
cout << "2 amount is " << invoice2. getInvoiceAmount ( x2, y2 ) << endl;
cout << endl;
// test program that using data entered by user
cout << "*** Test Program ***";
// variables
string p_Number;
string p_Desc;
int ppi;
int p_Quantity;
// get data from user
cout << "\nPlease enter Part Number: ";
cin >> p_Number;
cout << "Please enter Part Description: ";
cin >> p_Desc;
cout << "Please enter Price Per Item: ";
cin >> ppi;
cout << "Please enter Quantity: ";
cin >> p_Quantity;
//using set functions
invoice1. setPartNumber(p_Number) ;
invoice1. setPartDescription(p_Desc) ;
invoice1. setPrice(ppi) ;
invoice1. setQuantity(p_Quantity) ;
// using get functions, invoice amount function and output result
cout << "\nPart number is " << invoice1. getPartNumber() ;
cout << "\nPart description is " << invoice1. getPartDescription() ;
cout << "\nPrice is " << invoice1. getPrice() ;
cout << "\nQuantity is " << invoice1. getQuantity() ;
cout << "\nInvoice amount is " << invoice1. getInvoiceAmount(invoice1. getPrice() , invoice1. getQuantity() ) ;
}/

Part :B

#include <cstdio>
#include <cstdlib>
#include <iostream>
using namespace std;
class Invoice
{p
ublic:
Invoice(string initPartNumber, string initPartDescription, int initQuantity, int initPrice) ;
void setPartNumber( string) ;
string getPartNumber() ;
void setPartDescription (string) ;
string getPartDescription() ;
void setQuantity( int ) ;
int getQuantity() ;
void setPrice( int ) ;
int getPrice() ;
int getInvoiceAmount(int, int) ;
private:
string partNumber;
string partDescription;
int quantity;
int price;
int invoiceAmount;
};
 

Part :C

#include <cstdio>
#include <cstdlib>
#include <iostream>
using namespace std;
#include "Invoice. h"

// initialization with constructor
Invoice: : Invoice( string initPartNumber, string initPartDescription, int initQuantity, int initPrice)
{
setPartNumber( initPartNumber ) ;
// cout << "Part Number set completed" << endl; // uncomment it if you want to see sequence
setPartDescription( initPartDescription ) ;
// cout << "Description set completed" << endl; // uncomment it if you want to see sequence
// if number is positive
if (initQuantity >= 0)
{
setQuantity( initQuantity ) ;
//cout << "Number set completed" << endl; // uncomment it if you want to see sequence
}/
/ if number is not positive it set as 0
if (initQuantity < 0)
{
quantity = 0;
cout << "Number can not be negative and set as 0" << endl;
}
// if number is positive
if (initPrice >= 0)
{
setPrice( initPrice ) ;
// cout << "Price set completed" << endl; // uncomment it if you want to see sequence
}
// if number is not positive it set as 0
if (initPrice < 0)
{
price = 0;
cout << "Price can not be negative and set as 0" << endl;
}
}/
/set function for Part Number
void Invoice: : setPartNumber( string initPartNumber )
{
partNumber = initPartNumber;
}/

string Invoice: : getPartNumber()
{
return partNumber;
}/
/function for set desc
void Invoice: : setPartDescription ( string initPartDescription )
{
partDescription = initPartDescription;
}/
/function for get desc
string Invoice: : getPartDescription()
{
return partDescription;
}/
/function for set number
void Invoice: : setQuantity( int initQuantity)
{
quantity = initQuantity;
}/
/function for get number
int Invoice: : getQuantity()
{
return quantity;
}/
/function for set price
void Invoice: : setPrice( int initPrice)
{
price = initPrice;
}/
/function for get price
int Invoice: : getPrice()
{
return price;
}/
/function for get invoice amount
int Invoice: : getInvoiceAmount( int iQuantity, int iPrice)

{
if((iQuantity<0) | | (iPrice<0) )
{
cout << "Incorrect args! " << endl;
}
else
{
invoiceAmount = iQuantity * iPrice;
}r
eturn invoiceAmount;
}