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You have two lists and want to find items that exist in only one or the other list.
To compare two lists, use the Compare-Object cmdlet:
PS > $array1 = "Item 1","Item 2","Item 3","Item 12" PS > $array2 = "Item 1","Item 8","Item 3","Item 9","Item 12" PS > Compare-Object $array1 $array2 -IncludeEqual InputObject SideIndicator ----------- ------------- Item 1 == Item 3 == Item 12 == Item 8 => Item 9 => Item 2 <=
The Compare-Object cmdlet lets you compare two lists. By default, it shows only the items that exist exclusively in one of the lists, although its -IncludeEqual parameter lets you include items that exist in both. If it returns no results, the two lists are equal.
For more information on comparing data, see Chapter 22.
Chapter 22