Sort and delete duplicates in multidimensional array - powershell

Question

I have an multidimensional Array and want to sort it by the date and delete the duplicate entries (by date).
$arrayPlaces = [System.Collections.ArrayList]#()
and that is how the Array looks like:
$arrayPlaces.Add(($mailBarcodeInformation[2], $mailScannedStart.Substring(22), "", "", "", "", "", ""))
The empty fields are filled later. The second field $mailScannedStart.Substring(22) is the time and the Array should be sorted by that and the duplicates should also be removed.
I searched a lot but couldn't find any help.

Answer 1

A common approach is to add a custom object into an array and use the buit-in cmdlet sort -unique. It's much more readable:
$arrayPlaces = [System.Collections.ArrayList]#()
#.........
$arrayPlaces.Add([PSCustomObject]#{
barcode = $mailBarcodeInformation[2]
time = $mailScannedStart.Substring(22)
foo1 = ''
foo2 = ''
foo3 = ''
}) >$null
#...........
$sorted = $arrayPlaces | sort time -Unique
However, since you already use a .NET class you can switch to a fast .NET SortedDictionary, which automatically sorts and deduplicates the collection when items are added:
$arrayPlaces = [Collections.Generic.SortedDictionary[string,array]]#{}
Adding and overwriting the old value:
$key = $mailScannedStart.Substring(22)
$arrayPlaces[$key] = $mailBarcodeInformation[2], $key, "", "", "", "", "", ""
Checking for presence of an item using its key:
if ($arrayPlaces.ContainsKey($key)) { ....... }
Removing:
[void]$arrayPlaces.Remove('foo')
Accessing:
$items = $arrayPlaces['foo']
$item = $arrayPlaces['foo'][0]
Enumerating (faster):
foreach ($items in $arrayPlaces.Values) {
# .........
}
Enumerating/pipelining (slower):
$arrayPlaces.Values | foreach { $_[0] = $_[1] + $[2] }