Variable stuck in a "for" powershell - powershell

Question

I am have been trying to get out, the variable $groupUsers (array) that is stuck in inside a for.
I have being researching about the scopes of the variables an I have found that a variable need to be global if I want it to be available in all the function.
I have tried putting the array outside the foreach, the if the for and even converting it to $global:groupUsers but it doesn't work.
function get-localadmins{
[cmdletbinding()]
param( [string[]] $machineslist)
#split computers list
$separator = ","
$option = [System.StringSplitOptions]::RemoveEmptyEntries
$computerSplit = $machineslist.Split($separator, 20000 ,$option)
#input credentials
$credential = Get-Credential kimo\admin0987
######## Create empty array to use in the for #####
$groupUsers = #()
foreach ($computer in $computerSplit)
{
$session = new-pssession -computername $computer -Credential $credential
If ($? -eq $false )
{
$alert = "La conexion remota de ""PSSRemoting""no pude ser establecida con este equipo porfavor verifica WinRM has been updated to receive requests. WinRM service type changed successfully. WinRM service started. WinRM has been updated for remote management. WinRM firewall exception enabled. que la politica de este activada o corre el commando asdfjsfda para habilitar powershell remoto "
}
else
{
new-pssession -computername $computer -Credential $credential
$admingroup2 = Invoke-Command -ComputerName $computer -Credential $credential -ScriptBlock {
$group = get-wmiobject win32_group -ComputerName localhost -Filter "LocalAccount=True AND SID='S-1-5-32-544'"
$query = "GroupComponent = `"Win32_Group.Domain='$($group.domain)'`,Name='$($group.name)'`""
$list = Get-WmiObject win32_groupuser -ComputerName localhost -Filter $query
$admingroup = $list | select PartComponent # | % {$_.substring($_.lastindexof("Domain=") + 7).replace("`",Name=`"","\")}
$clean = $admingroup
for($i = 0; $i -lt $clean.length; $i += 1)
{
$string = $clean[$i] | Out-String
$domainPosition = $string.lastindexof('Domain=') + 7
$nextComma = $string.substring($domainPosition).indexOf(',')
$domain = $string.substring($domainPosition,$nextComma-1)
$namePosition = $string.lastindexof('Name="') + 6
$name = $string.substring($namePosition)
#####this is the variable that I can get outside the for ######
$groupUsers += $domain + "\" + $name
Write-Host $groupUsers "inside for"
}
Write-Host $groupUsers "outside for"
}
}
}
############### I need to get the variable here ###################
$groupUsers| ConvertTo-Html
Write-Host $groupUsers "out side the for-each "
}
$222 = get-localadmins localhost,machine1,machine2

Answer 1

It seems like the only problem you have here is that you aren't getting $groupUsers returned from the function. That's because you're never returning it!
Write-Host writes directly to the host application as a way of showing data without including it in the pipeline.
To return data, use Write-Object or just don't qualify it at all:
$groupUsers += $domain + "\" + $name
Write-Host $groupUsers "inside for"
}
Write-Host $groupUsers "outside for"
$groupUsers # this will return it
}
Then your $222 variable will contain the value.
You don't need $Global scope here.