Description
Building the Drink Machine
Write a program that simulates a soft drink machine. The program will need several classes: DrinkItem,
DrinkMachine and Receipt. For each of the classes you must create the constructors and member
functions required below. You can, optionally, add additional private member functions that can be used
for doing implementation work within the class.
DrinkItem class
The DrinkItem class will contains the following private data members:
name: Drink name (type of drink – read in from a file). Type is std::string.
price: Drink cost (the retail cost of one drink). This is the price the customer will pay for one
drink of this type. This is also read in from a file. Type is double.
quantity: Number of drinks, of this type, in the machine. Initial value is read in from a file.
This is also updated by the program. Type unsigned int.
purchased: Drinks purchased. Initially 0. Updated whenever a drink is purchased. Type is
unsigned int.
sales: This is used to keep track of the amount of money paid for all of the drinks purchased.
Every time there is a successful purchase the amount of the purchase should be added to sales.
You need to initially set this to 0. Type is double.
You need to have public accessors for all of the above (five) data members. Make sure you accessors are
const member functions. Only the price, and name data members should have a mutator functions. So
you will have five get member functions (accessors) but only two set member functions (mutators).
Example:
The prototype for the accessor for price would be:
double getPrice() const;
and the mutator would be:
void setPrice(double newPrice);
CS2336.006 Assignment 2 2
You will also need the following additional public member functions / constructors:
void addDrinks(unsigned int amount)
When this member function is called your program needs to update the quantity by the specified
amount.
bool purchase()
The purchase member function will check to see if there are any drinks left. If there is at least 1 drink
remaining the purchase member function will subtract 1 drink from the number of drinks, add 1 to the
drinks purchased, add the cost of the drink to sales, and return a true value.
If the number of drinks is 0 when this member function is called no member data should be updated and
a value of false should be returned.
DrinkItem constructors (two total)
The DrinkItem class will have one constructor that takes the input values name, price and quantity (in
that order). The purchased and sales member data variables will be set to 0.
The second constructor is a default constructor (no arguments) that will set the numeric values to 0 and
the name to “”;
Create a header file drinkitem.h for the class declaration and create a drinkitem.cpp file for the member
functions. You can inline the accessors and mutations. Do not inline any of the other member functions
and do not inline the constructors.
DrinkMachine class
The DrinkMachine class will contain the following data members:
An unsigned int that contains a version number. For this assignment this will have a value
of 1.
An unsigned int that contains the actual number of DrinkItem objects being used in the
drink item array.
An array of DrinkItem objects. Each element of the array will be a DrinkItem object. This
array will contain a maximum of 25 elements. You will keep track on the actual number in use
via the unsigned int value you created above.
An unsigned int that contains the maximum number of DrinkItem objects. This is used
internally by the drink machine to make sure you don’t put more than 25 DrinkItem objects
in the array.
CS2336.006 Assignment 2 3
The public member functions in the DrinkMachine class are:
DrinkMachine() constructor
The constructor will take no parameters. The various drink machine values will be read in from the file
drink.txt. The constructor will also write the drink machine values (read in from the file) to a file called
drink_backup.txt. This way you will have a backup copy of your file in case there are bugs in your code.
The first value in the input file, drink.txt, is the number of drink items. There will then be drink
information for each of the drink items specified by the first value in the file. A drink item is made up of
a name, price and quantity. The first drink item you read in will go into the array of DrinkItem value
at index 0. The next one will go into the entry with index 1, and so on. The sample file drink.txt
provided with the exercise. See the section
Input file drink.txt on page 5 for details.
~DrinkMachine() destructor
The destructor will write the current list of items back to the output file, drink.txt. This will include the
new quantity values for the DrinkItem objects.
unsigned int size() const
Returns the current number of DrinkItem entries being used by the drink machine. These are the
ones read in from the input file.
unsigned int max_size() const
Returns the maximum number of DrinkItem entries allowed in the drink machine.
DrinkItem& at(unsigned int index)
Return a reference to the drink item at the specified index.
const DrinkItem& at(unsigned int index) const
Returns a const reference to the specified drink item. This allows you to use a function that uses a
const DrinkItem reference. You cannot update the DrinkItem object in this case.
bool available(unsigned int drinkId) const
Return true if the drink item at index drinkId has a quantity of 1 or more. Return false otherwise.
double getPrice(unsigned int drinkId) const
Get the price of the item at the specified index.
CS2336.006 Assignment 2 4
Receipt purchase(unsigned int drinkId, double amount)
Purchase an item at the specified index. If the purchase worked return a Receipt object with any
change. If the drink could not be purchased (the quantity was 0) or if the funds were insufficient return
Receipt with change of 0 and either insufficient or empty turned on. Check for the funds amount first.
If the funds are enough for the purchase then check the quantity. Update the quantity and purchased
totals as appropriate. Note your return statement will look similar to the following:
Receipt purchase(unsigned int drinkId, double amount)
{
// code goes here
return Receipt(…); // where … is the rest of the constructor
}
You are returning back a temporary object here. The return type for the purchase member function is
also Receipt, which is a temporary object. The object will be deleted once it has been assigned in the
calling function. You do not want to return by reference, it needs to be a copied temporary object. You
also do not want to create it with the new operator or you will be creating a memory leak in your
program.
void addDrinks(unsigned int drinkId, unsigned int amount)
Add the specified number of drinks for the specified drink item index.
void print(std::ostream& outStream) const
Print out the current contents of the drink machine including the drink machine version, the number of
drink items in the machine and all of the information about the drink items (index, name, price,
quantity, number of drinks purchased, and the sales for this drink).
Here is a sample of the output (you must have all of this data in your output). Make sure you align the
output as shown here. Your spacing may be different.
Drink Machine Version 1
Number of entries: 8
Id Name Price $ Qty Sold Sales $
0 Cola 1.25 24 1 1.25
1 Root-beer 1.25 19 1 1.25
2 Lemon-lime 1.25 25 0 0.00
3 Water 1.00 39 1 1.00
4 Orange 1.25 0 5 6.25
5 Iced-tea 1.25 35 0 0.00
6 Grape 1.30 15 0 0.00
7 Iced-coffee 2.00 34 1 2.00
CS2336.006 Assignment 2 5
double sales() const
Calculate the sales for all drinks. This is the amount of the sales, not the quantity.
double sales(unsigned int drinkId) const
Calculate the sales for a specific drink. This is the amount of all sales of this drink, not the quantity. You
should have the DrinkMachine::sales(unsigned int) member function call the appropriate DrinkItem’s
getSales() member function.
Receipt class
The Receipt class is returned by the DrinkMachine::purchase member function. The calling function will
interrogate the Receipt object to see if the purchased worked or not.
You will need to determine the member data that needs to be in the class based on the following
member function requirements.
The Receipt class needs to have the following member functions. You will need to determine the format
of the constructor and the member data that has to be part of the class. You can inline the constructor
and member functions for this class. If you do this you will only have the Receipt.h header file and won’t
have the Receipt.cpp file.
bool success() const
Returns true if the purchase completed without any errors.
bool insufficient() const
Return true if the amount pass for the purchase was less than the purchase price. Note that the price
should be checked before you check the quantity. If the amount is insufficient you should not check the
quantity.
bool empty() const
Return true if the quantity was 0.
double getChange() const
Return the amount of change that is due to the purchaser of the drink. This amount is valid only if
success() returns true. If either insufficient() or empty() returns true the getChange() member
function must return 0.0.
Input file drink.txt
Here is a sample file that contains the information for one such Drink Machine:
CS2336.006 Assignment 2 6
8
Cola 1.25 25
Root-beer 1.25 20
Lemon-lime 1.25 25
Water 1.00 40
Orange 1.25 5
Iced-tea 1.25 35
Grape 1.30 15
Iced-coffee 2.00 35
Note that the drink names do not include any spaces in the text. The drink name is first, the cost of the
drink is second and the number of drinks in the machine at start up is third. Each value to be read in
from the file is a token and you can use the stream operator >> to read in the values from the file.
Your input file must be in the format above. You should try adding additional drink items to the file to
make sure you can handle up to 25 drinks. Here is an example with 9 drinks:
9
Cola 1.25 25
Root-beer 1.25 20
Lemon-lime 1.25 25
Water 1.00 40
Orange 1.25 5
Java-water 1.45 10
Iced-tea 1.25 35
Grape 1.30 15
Iced-coffee 2.00 35
Driver application
The driver application that makes use of the DrinkMachine is file project2.cpp and has been provided to
you. This code will make use of the DrinkMachine, DrinkItem and Receipt classes. You must not change
the driver code. If you have written the classes as specified above the driver code will work without any
changes.
Comments, variable names and so on.
Make sure your variable names have meaningful names and that you have included appropriate
comments in your application.
You must include the following as your first comments in your header files (.h) and in your .cpp files.
CS2336.006 Assignment 2 7
// Assignment 2 for CS 2336.002
// Programmer:
// Description:
//
Make sure you replace with your name. Make sure you include comments at
the top of your cpp file that describes what you are doing in the application code (the Drink Machine)
You need to ensure you have comments throughout your program and not just the comments at the top
of the program.
Files you need to submit
You need to submit the header files (.h) and source files (.cpp) for your classes:
drinkmachine.h
drinkmachine.cpp
drinkitem.h
drinkitem.cpp
receipt.h
receipt.cpp (you won’t have this one if you inline the class)
Note that you are not uploading the project.cpp file or the drink.txt file. You are not allowed to change
the driver code and the format of the drink.txt file must be as shown.
Grading:
20% of the grade will for comments you have in your program, for having meaningful variable names,
and for formatting your code as is shown in the C++ text book.
80% will be for the program itself. Make sure you do all of the parts and that your output matches what
is shown in the sample runs.
Here is a sample run of the application
The output that follows shows the successful purchase of drinks, trying to purchase a drink and not
having enough money, and trying to buy a drink that is out of stock. This is using the default input file
and the driver code that has been provided to you.
Menu # Name Price $ Qty
0 Cola 1.25 25
1 Root-beer 1.25 20
2 Lemon-lime 1.25 25
3 Water 1.00 40
4 Orange 1.25 5
5 Iced-tea 1.25 35
6 Grape 1.30 15
CS2336.006 Assignment 2 8
7 Iced-coffee 2.00 35
8 exit program
Enter a menu item: 0[Enter]
Enter the amount of the purchase: 1.25[Enter]
Your purchase of Cola succeeded. There was no change
Menu # Name Price $ Qty
0 Cola 1.25 24
1 Root-beer 1.25 20
2 Lemon-lime 1.25 25
3 Water 1.00 40
4 Orange 1.25 5
5 Iced-tea 1.25 35
6 Grape 1.30 15
7 Iced-coffee 2.00 35
8 exit program
Enter a menu item: 4[Enter]
Enter the amount of the purchase: 1.5[Enter]
Your purchase of Orange succeeded. Your change is $0.25
Menu # Name Price $ Qty
0 Cola 1.25 24
1 Root-beer 1.25 20
2 Lemon-lime 1.25 25
3 Water 1.00 40
4 Orange 1.25 4
5 Iced-tea 1.25 35
6 Grape 1.30 15
7 Iced-coffee 2.00 35
8 exit program
Enter a menu item: 4[Enter]
Enter the amount of the purchase: 1[Enter]
You need additional money for the purchase
Menu # Name Price $ Qty
0 Cola 1.25 24
1 Root-beer 1.25 20
2 Lemon-lime 1.25 25
3 Water 1.00 40
4 Orange 1.25 4
5 Iced-tea 1.25 35
6 Grape 1.30 15
7 Iced-coffee 2.00 35
8 exit program
Enter a menu item: 4[Enter]
CS2336.006 Assignment 2 9
Enter the amount of the purchase: 2[Enter]
Your purchase of Orange succeeded. Your change is $0.75
Menu # Name Price $ Qty
0 Cola 1.25 24
1 Root-beer 1.25 20
2 Lemon-lime 1.25 25
3 Water 1.00 40
4 Orange 1.25 3
5 Iced-tea 1.25 35
6 Grape 1.30 15
7 Iced-coffee 2.00 35
8 exit program
Enter a menu item: 4[Enter]
Enter the amount of the purchase: 1.25[Enter]
Your purchase of Orange succeeded. There was no change
Menu # Name Price $ Qty
0 Cola 1.25 24
1 Root-beer 1.25 20
2 Lemon-lime 1.25 25
3 Water 1.00 40
4 Orange 1.25 2
5 Iced-tea 1.25 35
6 Grape 1.30 15
7 Iced-coffee 2.00 35
8 exit program
Enter a menu item: 7[Enter]
Enter the amount of the purchase: 2.01[Enter]
Your purchase of Iced-coffee succeeded. Your change is $0.01
Menu # Name Price $ Qty
0 Cola 1.25 24
1 Root-beer 1.25 20
2 Lemon-lime 1.25 25
3 Water 1.00 40
4 Orange 1.25 2
5 Iced-tea 1.25 35
6 Grape 1.30 15
7 Iced-coffee 2.00 34
8 exit program
Enter a menu item: 4[Enter]
Enter the amount of the purchase: 2[Enter]
Your purchase of Orange succeeded. Your change is $0.75
CS2336.006 Assignment 2 10
Menu # Name Price $ Qty
0 Cola 1.25 24
1 Root-beer 1.25 20
2 Lemon-lime 1.25 25
3 Water 1.00 40
4 Orange 1.25 1
5 Iced-tea 1.25 35
6 Grape 1.30 15
7 Iced-coffee 2.00 34
8 exit program
Enter a menu item: 4[Enter]
Enter the amount of the purchase: 2[Enter]
Your purchase of Orange succeeded. Your change is $0.75
Menu # Name Price $ Qty
0 Cola 1.25 24
1 Root-beer 1.25 20
2 Lemon-lime 1.25 25
3 Water 1.00 40
4 Orange 1.25 0
5 Iced-tea 1.25 35
6 Grape 1.30 15
7 Iced-coffee 2.00 34
8 exit program
Enter a menu item: 4[Enter]
Enter the amount of the purchase: 2[Enter]
Your selection is empty
Menu # Name Price $ Qty
0 Cola 1.25 24
1 Root-beer 1.25 20
2 Lemon-lime 1.25 25
3 Water 1.00 40
4 Orange 1.25 0
5 Iced-tea 1.25 35
6 Grape 1.30 15
7 Iced-coffee 2.00 34
8 exit program
Enter a menu item: 4[Enter]
Enter the amount of the purchase: 1[Enter]
You need additional money for the purchase
Menu # Name Price $ Qty
0 Cola 1.25 24
1 Root-beer 1.25 20
CS2336.006 Assignment 2 11
2 Lemon-lime 1.25 25
3 Water 1.00 40
4 Orange 1.25 0
5 Iced-tea 1.25 35
6 Grape 1.30 15
7 Iced-coffee 2.00 34
8 exit program
Enter a menu item: 4[Enter]
Enter the amount of the purchase: 2[Enter]
Your selection is empty
Menu # Name Price $ Qty
0 Cola 1.25 24
1 Root-beer 1.25 20
2 Lemon-lime 1.25 25
3 Water 1.00 40
4 Orange 1.25 0
5 Iced-tea 1.25 35
6 Grape 1.30 15
7 Iced-coffee 2.00 34
8 exit program
Enter a menu item: 9[Enter]
The menu item is not valid
Menu # Name Price $ Qty
0 Cola 1.25 24
1 Root-beer 1.25 20
2 Lemon-lime 1.25 25
3 Water 1.00 40
4 Orange 1.25 0
5 Iced-tea 1.25 35
6 Grape 1.30 15
7 Iced-coffee 2.00 34
8 exit program
Enter a menu item: x[Enter]
Invalid input “x” has been discarded
Menu # Name Price $ Qty
0 Cola 1.25 24
1 Root-beer 1.25 20
2 Lemon-lime 1.25 25
3 Water 1.00 40
4 Orange 1.25 0
5 Iced-tea 1.25 35
6 Grape 1.30 15
CS2336.006 Assignment 2 12
7 Iced-coffee 2.00 34
8 exit program
Enter a menu item: 1[Enter]
Enter the amount of the purchase: 2[Enter]
Your purchase of Root-beer succeeded. Your change is $0.75
Menu # Name Price $ Qty
0 Cola 1.25 24
1 Root-beer 1.25 19
2 Lemon-lime 1.25 25
3 Water 1.00 40
4 Orange 1.25 0
5 Iced-tea 1.25 35
6 Grape 1.30 15
7 Iced-coffee 2.00 34
8 exit program
Enter a menu item: 3[Enter]
Enter the amount of the purchase: 1[Enter]
Your purchase of Water succeeded. There was no change
Menu # Name Price $ Qty
0 Cola 1.25 24
1 Root-beer 1.25 19
2 Lemon-lime 1.25 25
3 Water 1.00 39
4 Orange 1.25 0
5 Iced-tea 1.25 35
6 Grape 1.30 15
7 Iced-coffee 2.00 34
8 exit program
Enter a menu item: 8[Enter]
Drink Machine Version 1
Number of entries: 8
Id Name Price $ Qty Sold Sales $
0 Cola 1.25 24 1 1.25
1 Root-beer 1.25 19 1 1.25
2 Lemon-lime 1.25 25 0 0.00
3 Water 1.00 39 1 1.00
4 Orange 1.25 0 5 6.25
5 Iced-tea 1.25 35 0 0.00
6 Grape 1.30 15 0 0.00
7 Iced-coffee 2.00 34 1 2.00
CS2336.006 Assignment 2 13
The total sales is $11.75
Now restock the drink machine
Drink Orange is out of stock. Restocking with 5 drinks.
Drink Machine Version 1
Number of entries: 8
Id Name Price $ Qty Sold Sales $
0 Cola 1.25 24 1 1.25
1 Root-beer 1.25 19 1 1.25
2 Lemon-lime 1.25 25 0 0.00
3 Water 1.00 39 1 1.00
4 Orange 1.25 5 5 6.25
5 Iced-tea 1.25 35 0 0.00
6 Grape 1.30 15 0 0.00
7 Iced-coffee 2.00 34 1 2.00
Let me know if you have any questions.
