I'm coding a C# app and I need a good datatype for storing an array of classes that uses a unique ID as the key. I'm used to Maps in C++
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I've been looking at the HashTable and it seems complicated. I have a simple class that has an ID, X, Y and thats it. I want an array/collection of my object that uses the ID as the index.
So when I receive a new object I could do the following
myObjectList[newObject.ID]
My goal is to not duplicate objects in the list. As I said I'm used to CMapStringToPtr maps in MFC
I'm not sure what the complication of concern is. Hashtables are relatively straightforward to use. They're certainly quick, compared to some other collections.
Hashtables do allow multiple objects with the same key, which is what you'd get if you use the Add method to add new objects with the same key. But setting the Item property *replaces* any existing object that has the same key, so you can have it either way, depending on what you need.
So you could do something like:
Hashtable myHash = new Hashtable();
myHash.Item[newObject.ID] = newObject;
which would result in any existing objects with a key of newObject.ID being replaced with the new object.
More at:
Hashtable class: http://msdn2.microsoft.com
Add method: http://msdn2.microsoft.com
Item property: http://msdn2.microsoft.com
Other members: http://msdn2.microsoft.com
BTW, another reasonable option (if you're using .NET 2.0 or later) might include:
System.Collections.Generic
Business Accounts
Answer for Membership
by: ThogekPosted on 2007-05-17 at 17:35:55ID: 19112949
Depending on exactly what you're working with and trying to do, a Hashtable might do you well. (See http://msdn2.microsoft.com
There're also an interesting assortment of built-in collections in System.Collections.Special