Trouble with $arrayList.Remove($item) - powershell

Question

I am having trouble with this.
What i am trying to do is I have 2 different array, and I am trying to exclude $items in $ignore from $users
I can't use where $users | where {$ignore -notcontains $_} because the string in the $ignore array may contain wildcard (e.g., admin*)
But here is the main problem, when I matched the $item that i want to remove, it removes my entire array instead of the selected value.
[System.Collections.ArrayList]$users = Get-ADUser -Filter * | Select Name
$users = $users.name
$ignore = $audArr[5] -Split(",")
foreach ($item in $ignore) {
if ($item.Contains("*")) {
foreach ($user in $users) {
$matchResult = $user -like $item
if ($matchResult -eq $true){
$users = $users.Remove($item)
}
}
}
else {
$users = $users.Remove($item)
}
}
However, I if i try to .Add it works despite showing error
Cannot convert the "3" value of type "System.Int32" to type "System.Collections.ArrayList".
At C:\users\administrator\desktop\scannerTest.ps1:326 char:17
+ $users = $users.Add($item)
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidArgument: (:) [], RuntimeException
+ FullyQualifiedErrorId : ConvertToFinalInvalidCastException
Also, since i am already asking about powershell items.. Does anyone know what how to get LogonTime, KickoffTime via powershell? Adn what is ACB?

Answer 1

Santiago Squarzon's helpful answer uses a good approach with regex matching. We can further enhance the regex matching to include a combination of wildcard and exact matches.
$users = 'John Doe','Wolverine','Mr. Pants','Administrator','Jane Doe','Master Administrator'
# two exact matches and one wildcard match
$ignore = 'john doe','jane doe','admin*'
$regex = '^({0})$' -f (($ignore -replace '\*','.*') -join '|')
# List users who don't match $ignore
$users -notmatch $regex # Jane Doe, John Doe, Administrator not listed
If you must use an ArrayList, you can apply the same technique as above by
removing successful matches:
[collections.ArrayList]$users = 'John Doe','Wolverine','Mr. Pants','Administrator','Jane Doe','Master Administrator'
# two exact matches and one wildcard match
$ignore = 'john doe','jane doe','admin*'
$regex = '^({0})$' -f (($ignore -replace '\*','.*') -join '|')
$users -match $regex | Foreach-Object {
[void]$users.Remove($_)
}
Explanation:
In regex, alternations (basic OR logic) are separated by |. .* greedily matches any number of characters in a string. ^ denotes the beginning of a string. $ denotes the end of a string. Putting that all together, your exact matches would look like ^exact$ and your partial matches would look like ^admin.*$ (for admin*) or ^.*admin.*$ (for *admin*). Using alternation, you can combine those matches for an OR effect with ^(admin.*|Benjamin Dover|Johnny Lawrence)$.

Answer 2

What you're trying to do could be simplified to something like this:
Create a test case, the array will have User00 to User10 plus Administrators and Domain Admins.
$ignore = #(
'Administrators'
'Domain Admins'
'User05'
'User10'
)
[System.Collections.ArrayList]$users = 0..10 |
ForEach-Object { [pscustomobject]#{Name="User{0:00}" -f $_} }
$users.Add([pscustomobject]#{Name="Administrators"})
$users.Add([pscustomobject]#{Name="Domain Admins"})
Now you can simply use the .Where(..) method filtering those elements of the $users array that do not match the $ignore array on one side and those that do match on the other side.
$toIgnore = $ignore -join '|'
$notIgnoredUsers, $ignoredUsers = $users.Where({$_.Name -notmatch $toIgnore},'Split')
$notIgnoredUsers
Name
----
User00
User01
User02
User03
User04
User06
User07
User08
User09
$ignoredUsers
Name
----
User05
User10
Administrators
Domain Admins
As for how you're using the .Remove(..) method, since it doesn't produce any output, by doing $users = $users.Remove($item) you're actually setting the variable to null:
PS /> [System.Collections.ArrayList]$arr = 'one','two','three'
PS /> $arr = $arr.Remove('one')
PS /> $null -eq $arr
True
If you want to remove one from the list you would simply do $arr.Remove('one').