Function return array in PowerShell - arrays

Question

I have a problem when I'm trying to return an array from a PowerShell function.
My function:
function filter-SWCluster {
param($Path, $FolderList)
$OldSWCluster = New-Object System.Collections.ArrayList
ForEach ($y in $FolderList) {
Get-ChildItem -Path $Path -Filter $y* | sort { [version]($_.Name -replace '^.*_(\d+(\.\d+){1,3})$', '$1') } -Descending | Select-Object -skip 3 | ForEach-Object { $OldSWCluster.Add($Path + "\" + $_) }
}
Write-Output $OldSWCluster
}
The function call:
$FilerSWCluster = filter-SWCluster $NetworkPath $SWCluster
The output I get:
0 1 \\server.domain\C$\TEMP\Folders\Testcluster_1.0.2 \\server.domain\C$\TEMP\Folders\Testcluster_1.0.1
The output I want and need would be:
\\server.domain\C$\TEMP\Folders\Testcluster_1.0.2 \\server.domain\C$\TEMP\Folders\Testcluster_1.0.1
I need just the paths. I know there will already be some solutions, but please excuse me. I didn't find one which was working for me or I were to dumb to use it right (could be).

Answer 1

You could also wrap the Add method with the [void] class accelerator. It will hide any output, like this:
function filter-SWCluster {
param($Path, $FolderList)
$OldSWCluster = New-Object System.Collections.ArrayList
ForEach ($y in $FolderList) {
Get-ChildItem -Path $Path -Filter $y* | sort { [version]($_.Name -replace '^.*_(\d+(\.\d+){1,3})$', '$1') } -Descending | Select-Object -skip 3 | ForEach-Object { [void]$OldSWCluster.Add($Path + "\" + $_) }
}
Write-Output $OldSWCluster
}

Answer 2

wOxxOm already provided you a solution to your problem. However, consider to just return the path using a simple select. You also don't have to join the path since the FullName property already contains the full path:
function filter-SWCluster {
param($Path, $FolderList)
ForEach ($y in $FolderList) {
Get-ChildItem -Path $Path -Filter $y* |
sort { [version]($_.Name -replace '^.*_(\d+(\.\d+){1,3})$', '$1') } -Descending |
Select-Object -skip 3 |
select -ExpandProperty FullName
}
}