This program allows a user to generate bills for customer orders. It includes classes for CustomerAccount, Order, and Item that store customer, order, and item information respectively. The main program displays a menu to add items to an order and check out, calculating the total charges. Functions are included to add, edit, and delete customer and order information as well as item details. The program is designed to be implemented as a multi-file C program.

1. You are to write a program that computes customer 's bill for
his/her order in an online processing system. The different
component of the program are The CustomerAccount class The
Order class The Item class The main program The
CustomerAccount class will have the customers' information. It
will also keep track of customerID, CustomerName, Address,
and phoneNumber. The responsibilities for this class are:
AddCustomer, EditCustomer, and deleteCustomer The Order
class will have information about customer order. It can update
the charges for the customer order. It will keep track of
orderID, customerID, productID, totalCharge. The
responsibilities for this class are: CreateOrder and EditOrder
The Item class will have information about items. It can update
the totalCharge variable of the Order class. It will keep track of
productID, productPrice, and productDescription. The
responsibilities for this class are: EditProduct, and
SelectProduct Design the main so that it have a menu that
allows the user to add items to the customer order, and check
the customer out by showing the total charges. When the
customer checks out, the total charges should be displayed.
You need to writer constructors and destructors, get
functions(to retrieve appropriate attributes) and set functions
(to set attribute values) for each class. And any other required
functions to perform the requirements The parameters and
return types of each function and class member function should
be decided in advance (during the analysis and design phase).
Think about what attributes to include in each class Think of
useful member functions for each class The program will be
best implemented as a multi-file program.
Solution

2. You didn`t mention about in which language you need this
program so I am giving you the program in C language for bill
generator
#include "stdio.h"
#include "conio.h"
#include "valid.c"struct purch_detail
{
char item_desc[20];
int up; //up= unit price
int quantity;
};
void display();
void entryData();
void readFile();
void getName(char *str);
void getWriteFileName(char *);
void getReadFileName(char *);
void getzeroInteger(char *_chr, int *_value);
int count=0;
int tp=0; //tp= total price
int ta=0; //ta= total amount
char opt;
char filename [14];
FILE *fp;

3. struct purch_detail *pd_ptr, *tmptr;
void main()
{
clrscr();
pd_ptr = (struct purch_detail *) malloc(sizeof(struct
purch_detail) * 10);
tmptr = pd_ptr;
printf(" Do you want to create the data file type 'y' for yes
and 'n' for no.");
scanf("%c", &opt);
fflush(NULL);
if( opt == 'y' || opt == 'Y')
{ printf(" You can generate bill of maximum 10 item. ");
getWriteFileName(filename);
display();
}
elseif( opt == 'n' || opt == 'N')
{ getReadFileName(filename);
readFile();
}
getch();
}
void entryData()
{

4. while(1)
{
printf(" Enter item name : ");
getName(tmptr->item_desc);
getPosInteger("Enter unit price of the item : ", &tmptr->up);
getzeroInteger("Enter no of quantity purchased : ", &tmptr-
>quantity);
if(tmptr->quantity == 0)
break;
count ++;
if (count >= 10)
break;
/* if ( count % 2 == 0)
if ( (pd_ptr = (struct purch_detail *) realloc(pd_ptr,
sizeof(struct purch_detail) * 2)) == NULL)
{ printf("Realloc failed. No enough memory available.");
break;
}
*/
tmptr++;
}
}
void display()
{
tmptr = pd_ptr;

5. fprintf(fp," Item Unit Price Quantity Total Price ");
fprintf(fp,"
_____________________________________________________
_");
printf(" Item Unit Price Quantity Total Price ");
printf("
_____________________________________________________
_");
while(1)
{
tp = tmptr->up * tmptr->quantity ;
fprintf(fp, " %-20s %4d %4d %5d", tmptr->item_desc, tmptr-
>up, tmptr->quantity, tp);
printf(" %-20s %4d %4d %5d", tmptr->item_desc, tmptr->up,
tmptr->quantity, tp);
//printf("");
ta += tp;
count--;
if ( count <= 0)
break;
tmptr++;
}
fprintf(fp, "
_____________________________________________________
_");

6. fprintf(fp, " ttt Total Amount : %5d", ta);
printf("
_____________________________________________________
_");
printf(" ttt Total Amount : %5d", ta);
}
void getWriteFileName(char *fname)
{
printf("Enter Output File name maxium 14 character : ");
scanf("%s", fname);
if( ( fp = fopen(fname, "wt") ) == NULL )
{ fclose(fp);
printf(" Invalid file name entered.");
}
else
entryData();
}
void getReadFileName(char *fname)
{
printf("Enter Input File name maxium 14 character : ");
scanf("%s", fname);
if( ( fp = fopen(fname, "r+t") ) == NULL )
{ fclose(fp);
printf(" Invalid file name entered.");
}

7. }
void readFile()
{
char chr;
while( feof(fp) == 0)
{
chr = getc(fp);
printf("%c",chr);
}
}
void getName(char *str)
{
int count1=0;
char *getstr;
char readch='0';
int errorflag = 0;
fflush(NULL);
getstr = str;
while(1)
{
scanf("%c", &readch);
if( readch == ' ')
break;
*getstr = readch;
count1++;

8. getstr++;
if( count1 >= 20 )
break;
}
fflush(NULL);
if(errorflag)
getName(str);
*getstr='0';
}
void getzeroInteger(char *_chr, int *_value)
{
float tempval =1;
int _ival=0;
printf(" %s", _chr);
_scaint = scanf("%f", &tempval);
fflush(NULL);
if ( _scaint != 0 )
{
_ival = tempval;
if ( tempval < 0 )
{
printf("%s", " You should enter value greater then or equal
to zero. Enter the value again...");
getzeroInteger(_chr, _value);

9. }
elseif ( _ival != tempval)
{
printf("%s", " Error(decimal value). It will be truncated the
digit after the percision. Enter integer number only.");
getzeroInteger(_chr, _value);
}
elseif( ! ( (tempval >= -32768 ) && (tempval <= 32767 ) ) )
{
printf("%s", " Error out of range entry. You should enter
integer value in the range of -32768 to 327678 only.");
getzeroInteger(_chr, _value);
}
else
{
*_value = (int) tempval;
}
}
else
{
printf(" %s","Error in entry. Enter integers only.");
getzeroInteger(_chr, _value);
}
}