$Oldest = $Results | Where-Object { $_.Type -eq 'Main' } | Sort-Object LastUsed | Select-Object -First 10
Above my command tries to find the 10 oldest dates and then I act on them. My issue is that sometimes the date is blank or $null
How can I push the blank or $null to the top of the list and find them with the oldest?
The following should place $null values first in the sort order, before the objects with the oldest dates.
Sort-Object { [bool] $_.LastUsed }, LastUsed
The first Sort-Object criterion, [bool] $_.LastUsed, maps $null values to $false and non-null values to $true, and since $false sorts before $true, objects with $null values in their .LastUsed property are placed first in the sort order.
Those with non-null .LastUsed values sort according to those values, thanks to the second sort criterion (property).