Page 341 - Microsoft Office Excel 2003 Programming Inside Out

Developing Class Modules

An item is removed from the collection by calling the Remove method and specifying either
the relative position of the object or the value of the Name property. In either case, the
Remove method from the Collection object is used to remove the item from the underlying
collection.

Public Sub Remove(key As Variant)

MyPlants.Remove key
End Sub
Chapter 14
In the same fashion, the Count method returns the number of items in the collection by call­
ing the underlying Count method associated with the Collection object.

Public Function Count() As Long
Count = MyPlants.Count

End Function
The Clear method is useful if you want to delete all the objects in the collection. This routine
just destroys the underlying Collection object and then creates a new instance of the Collection
object.

Public Sub Clear()

Set MyPlants = Nothing
Set MyPlants = New Collection
End Sub

The Item method returns a single item from the collection. Like the Remove and Count meth­
ods, this item simply calls the Collection object’s Item method.

Public Function Item(key As Variant) As Plant

Set Item = MyPlants.Item(key)
End Function

The following routine is a macro that iterates through the collection class that was just cre­
ated. The macro begins by creating a new Plants object named MyPlants, which contains a
collection of Plant objects. Then the code calls the SampleData method, which simply adds
some sample objects to the collection.

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Part 4: Advanced VBA