In Chapter 2, you learned that when building WatchKit user interfaces, you have to know at design time which user interface objects you need and you must include them all in the storyboard. In some cases, this just isn’t possible. Suppose, for example, that you wanted to display the results of a database query in rows, with one row (and hence one group of user interface objects) for each query result. In general, you can’t know in advance how many query results there will be. You could try to work around this by adding a fixed number of groups to the storyboard and then, at run time, hiding any that you find you don’t need. You might be able to make that approach work in some cases, but it’s wasteful of scarce resources on the watch and doesn’t really work if you need to display different query results in different ways.