Find elements that are in array1 but NOT in array2

I pulled two lists of computers from two different tools: Array1

and Array2

.

Now I need to extract the ones that are in Array1

, but not in Array2

.

I managed to get all that fit by following these steps:

$matchingComp = @()

foreach ($SCCMcomputer in $SCCMcomputers) {
    foreach ($eWPTcomputer in $eWPTcomputers) {
        if ($SCCMcomputer.Computername -eq $eWPTComputer.Computername) {
            $obj = New-Object PSObject
            $obj | Add-Member -MemberType NoteProperty -Name "ComputerName" -Value $SCCMcomputer.Computername
            $matchingComp +=$obj
        }
    }
}

$matchingComp | Export-Csv $inEWPT -Delimiter "," -NoTypeInformation

      

        
        
        
      

    

But I still need the ones that are in $SCCMcomputer

, but NOT in $eWPTcomputers

...

I found some solutions on SO with other languages ​​(like Perl) but not for PowerShell.

UPDATE

I still am not getting the correct output in Excel with this formula:

the output looks like this:

means some are here and some are not. The result in powershell looks like this:

means 0KB is emtpy.

$SCCMcomputers | Export-Csv $sccmexport -Delimiter "," -NoTypeInformation
$eWPTcomputers | Export-Csv $ewptexport -Delimiter "," -NoTypeInformation
Compare-Object -ReferenceObject $SCCMcomputers -DifferenceObject $eWPTcomputers | ?{$_.sideIndicator -eq "=>"} |select inputobject | Export-Csv $inEWPT -NoTypeInformation
Compare-Object -ReferenceObject $SCCMcomputers -DifferenceObject $eWPTcomputers | ?{$_.sideIndicator -eq "=="} |select inputobject | Export-Csv $inBoth -NoTypeInformation
Compare-Object -ReferenceObject $SCCMcomputers -DifferenceObject $eWPTcomputers | ?{$_.sideIndicator -eq "<="} |select inputobject | Export-Csv $inSCCM -NoTypeInformation

      

        
        
        
      

    

And both column names (or whatever it was called) from SCCMcomptuers / eWPTcomputers are "Computername"

Any idea what I might be doing wrong? Both computer arrays are generated from SQL and in hashtables (I think it is called):, @{Computername=......}@{Computername....

something like this.

Update 2

foreach ($t in $sccmComputers) {
    $Test1 += $t.computername
}

$Test2 = @()
foreach ($t in $ewptComputers) {
    $Test2 += $t.computername
}

      

        
        
        
      

    

Removing the Hashtable header and just having arrays filled with strings works in fantasy ... does -Property computername

n't even work ...: S