Say you've got the following XML file:
<Root><Child /><Child /></Root>
Run this:
PS > $myDoc = [xml](Get-Content $pathToMyDoc)
PS > @($myDoc.SelectNodes("/Root/Child")).Count
2
PS > @($myDoc.Root.Child).Count
2
Now edit the XML file so it has no Child nodes, just the Root node, and run those statements again:
PS > $myDoc = [xml](Get-Content $pathToMyDoc)
PS > @($myDoc.SelectNodes("/Root/Child")).Count
0
PS > @($myDoc.Root.Child).Count
1
That 1 is annoying when you want to iterate over a collection of nodes using foreach if and only if there actually are any. This is how I learned that you cannot use the XML handler's property (dot) notation as a simple shortcut. I believe what's happening is that SelectNodes returns a collection of 0. When @'ed, it is transformed from an XPathNodeList to an Object[] (check GetType()), but the length is preserved because @ intelligently handles arrays. The dynamically generated $myDoc.Root.Child property (which essentially does not exist) returns $null. When $null is @'ed, it becomes an array of length 1.
