Inventory Project

Read the assignment before you start. The order in which aspects are described does not necessarily indicate the order in which you should write the code. It is up to you to use the concepts we have covered to design the classes and methods that will go into your program; your grade will be based on how well you do this. I would like to be able to give you credit for: classes, variables (types, instance, local), methods (parameters, return), conditionals (if, else), loops (while, for), and arrays.

Most of the credit for this programming project will be given for making good use of the programming ideas we've covered. A program that runs with nice output but does not make use of these ideas will get minimal credit. (i.e. if you've got one big main and that's all, you're doing something wrong). Assume you are writing a program that will later be updated and maintained (look at the EC for examples of the kind of changes your code should make it easy to do).

Correct projects will only use concepts and constructs we have covered in class. Feel free to reuse code you have already written or example code that has been given, but be sure to remove portions unrelated to the current assignment, and to update variable names, method names, etc.  Readability matters.

Use comments to clarify what your code is trying to do.  If code does not work; partial credit will only be given if comments explain what it was trying to do.

Programming Assignment

Our program is for a store with media items, and customers that can buy, own, and use these items.

A media item has a name and a price. Some items are currently on sale, which means the user can buy them at 10% lower than the actual price.  Users can "use" their media items; when basic media items are used, just print a message including the name, saying that it is in use.

The store has a list of all media items being sold and a list of customers. 

Each customer has a username, a balance, and a list of the media they have bought (which starts off empty, but they should be able to buy at least 10). 

The store has a list of at least 15 different media items to sell (some on sale), and a list of at least five customers [NOTE: Put the usernames of your customers in a comment at the top of your main class so I can find them easily when testing. Your life will be easier if all your customers have one word (no spaces) names.]

When the program starts, a customer can log in by typing in their username, or quit the program.   If they type in a wrong name (not an existing customer), they're just back to the option to log in or quit.

A customer who is logged in is shown a main menu where they can browse the media they already own, shop for more, add to their current balance, or log out. Once they log out we are back to letting someone else log in (or quit).

You do not have to worry about users entering completely invalid data (like a letter when you asked for a number). However, when asking how much to add to their balance, make them keep trying until they give a sensible (positive) answer.

When customers shop for new items, they are shown a list of all items in the store and can choose one from the list (probably by number).  If they choose a valid number, check if they have enough money in their balance for the price and if so add the chosen item to their list and deduct the price, otherwise tell them what went wrong.  (You do not have to remove the item they bought from the store, this is digital media and they just get a copy)

When customers browse their own media, they are shown all the items they own, and can choose from the list an item to use (probably by number). If they choose a valid number, use that media, otherwise tell them what went wrong. 

Whenever one customer logs out, we should be back at letting a customer log in or quit the program.  Within one run of the program, a customer should be able to log in, buy new media, and log out, then another customer can log in buy and log out, and then the first customer can log back in again later and see the media they bought earlier when they browse what they own.

hints: Firstempty. Put behaviors that a class does or that are all about a class' data in that class. Breaking up tasks into little methods make it easier to write and test. The main method is mostly in charge of dealing with the user: it calls methods to get things done -- make good use of parameters and return values to get data in and out of methods. Instance vars are expensive and only used for important characteristics of a class (local variables are cheap). Instance vars always mean we also have...