UITableViewCell identifiers? What exactly do they identify?

I'm just learning how to implement UITableViewControllers to control UITableViews with the iPhone SDK. I understand that it is common to use a method called dequeueReusableCellWithIdentifier: on a UITableViewCell instance that is passed a string that is designated a cell's identifier. This identifier allows for reusability of a cell instead of creating a new one from scratch every time a similar cell needs to be displayed in the UITableView.
My question is, what uniqueness exists within a cell to determine its reusability? That is, what exactly do these cell identifiers identify within a cell?
This would explain when it would be appropriate to designate more than one cell identifier.
I hope I'm making sense here. :P

Hi Brian - Cells are either recycled or manufactured in the tableView:cellForRowAtIndexPath: method of the table view data source, which uses the dequeueReusableCellWithIdentifier: method to either get a cell to recycle or find out that a new one needs to be built. The identifier becomes important when there are two or more kinds of cells--think of different makes and models of cars. From the row number passed to the cell factory (cellForRow..), the program logic will decide which model is needed. The identifier for that model will then be passed to dequeueReusable.., and if there aren't any reusable cells of that model, the factory makes a new one.
I understand that you already knew most of the above. I just wanted to restate it with a little more precision.
My question is, what uniqueness exists within a cell to determine its reusability? That is, what exactly do these cell identifiers identify within a cell?
Cells aren't going to be very different from each other until you start building custom cells. You can get a good overview of the possibilities from Customizing Cells in the +Table View Programming Guide for iPhone OS+. That section explains how cells can be customized by adding subviews, or by subclassing UITableViewCell.
You can find a really clear explanation of the above along with fun, instructive projects in Chapter 8 of +Beginning iPhone Development: Exploring the iPhone SDK+ Mark and LaMarche.
Hope that helps!
\- Ray

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UITableViewCell identifiers? What exactly do they identify?

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