What collection type should I use?

Question

Hey

I'm starting my project with C#.

This is my first one, so the question problably is something easy.

I have a list of cars, which I can lend out.

I want to use a list here for keeping the info about how many cars and which cars are lent out.

But I think it needs to be multidimensional, for example:

lent car, Owner, when, etc

Porsche, Jack, 2010, ...

Lada, Owen, 2001, ...

Wolkswagen, Mia, 2005, ...

What collection type should I use, can lists be multidimensional?

Or should I use List as the main type and insert arrays as individual positions?

Thanks

Felipe Ramos · Answer

Create a CarRental class to represent an instance of a rental something like class CarRental { public DateTime Created {get; private set; } public DateTime Due { get; private set; } public Car Item { get; private set; } public Customer Client { get; private set; } p ublic CarRental(Car car Customer customer int days) { Created = DateTime.Now; Due = Created.AddDays(days); Item = car; Client = customer; } }

Sam Hobbs · Answer

Busineses use applications such as Order Entry and Inventory and Accounts Receivables. Within AR there are customers. I think your application should be designed in a similar manner. So the cars would be the inventory. Your orders (whatever you want to call them) will consiste of customers and order items. Your application is more of a services-oriented application and there are many applications that have been developed for that. You might be able to find samples that can help you. One possibility is to use the DataTable class for the collection. Doing that will be more work for some things but it will be less work over-all. You can use the DataTable class even if you are not storing the data in a database but I assume you need to store the data somehow. Whatever you use for storing the data the DataTable class will probably make it easier.

Moose Pickard · Answer

Hi I've been working on the structure I figured it would be easier to make statistics and from overall programming perspective if I make only Car objects. I created an UML diagram I don't know if I got the symbols right (It isn't that important here). http://www.flickr.com/photos/54126948@N08/5001690602/ I figured I could use an interface for both car subclasses. But I don't know if it is possible to do this. The flow: User registers and adds their cars to the CarRental Class. Then they can rent cars out so the PersonalCar object should connect with the Rental interface. (Is it possible to do this on runtime?) The user can rent cars in so the car gets added as the RentedCar object. Thank you for youre previous help. Can you point me out the flaws in this architecture and maybe help me fix them.

Moose Pickard · Answer

Hi I would like to do it with car objects but where do save the information about the rented car. I mean who rented it when it was rented how long is it rented cost etc. I could add it all to the car object but it would be a messy object when was it rented doesn't seem to belong to a car. From OOP it wouldn't be good of course I am new to this field so I don't know where to make compromises between OOP and efficency. Or maybe I should make a new loan class? Also what's with Google Chrome not workinging when I try to reply it displays the loading but it doesn't complete I can't type in text into the field.

Adavesh Managaon · Answer

ArrayList is really a bad idea. Go for a Collection class like Class Car { public string CarModel {get; set;} public string CarOwner {get; set;} } Class Cars: ICollection { List oCarList; public Cars() { oCarList = new List } public void Add(Car item) { oCarList.Add(item); } public void Clear() { oCarList.Clear(); } public bool Contains(Car item) { //Implement as you need } public void CopyTo(string[] array int arrayIndex) { //implement as u need } public int Count { get { return oCarList.Count; } } public bool IsReadOnly { get { return false;} } public bool Remove(string item) { //implement as u need } public IEnumerator GetEnumerator() { foreach(Car car in oCarList) { yield return car; } } System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() { foreach(Car car in oCarList) { yield return car; } } } Now you can create a Car object & add it to cars collection. Simple right?

Majid Kamali · Answer

Hi Moose. You Can use a 2D array of Objects and with new operator change them in specific class object. For Example: object[] MyArray = new object[n 4]; // n is e.g number of cars for (int i = 0; i MyArray[i 0] = new Owner(); // Your Defined Class for (int i = 0; i MyArray[i 1] = new Car(); // Your Defined Class And so on.

Felipe Ramos · Answer

A boolean will do just fine. The other option you have if you want to get granular is an enumerator public enum CarStatus { Rented = 0 Stolen = 1 InLot = 2 } and in your Car class you would have a property for status public CarStatus Status {get;set;} Last thing- if you are using a list just create a list of your object List cars = new List (1); this way you dont have to worry about casting.

Moose Pickard · Answer

Hi How could I make a list with array objects so I could insert many things into one list position. List Cars = new List (); ??? Well I guess it is a simple library system I have 4 classes for now: Owner/Client CarLibrary Car CarSpec. I have thought about the structure of this thing. So Felipe you think I should have a availability boolean in Car class ?

Felipe Ramos · Answer

Moose I think once you figure out how to organize your data a List would be fine. For instance if you think about it like a simple library system in which you have your Car object with a status of Available/CheckOut and a Client object to track your borrowers you can get get away with having a list of cars and a list of clients. Maybe you can use a GUID as the ID for each car and have a list of ids in the client class to track what cars they have.

Mahesh Chand · Answer

ArrayList class is one of the most flexible with many methods and properties. However it does not support multi-dimension.