powershell add item to psobject

When executing the script, I get an error in the command “$CSV += $NieuwePC”
Method invocation failed because [System.Management.Automation.PSObject] does not contain a method named ‘op_Addition’.
I do not understand what this message meant and how to solve it.

$PATH = ‘N:\ApplicatieGebruik\applicatie gebruik.csv’
$CSV = Import-Csv $PATH
$Datum = get-date -format g

$Computer = $CSV | where {$_.Werkplek -eq “$env:computername”}
if($Computer) # computer bestaat
foreach($row in $CSV)
if ($row.Werkplek -eq “$env:computername”)
$row.Datum = $Datum
$row.Gebruiker = $env:username
else # computer bestaat niet
$NieuwePC = [pscustomobject] @{Werkplek = “$env:computername”; datum = “$Datum”; Gebruiker = “$env:username”}
$CSV += $NieuwePC
“werkplek toevoegen”

$CSV | Sort-Object { $_.Datum -as [datetime]} -Descending | Export-Csv $PATH -NoTypeInformation

From what I can tell, you are trying to add a new PC to a CSV if it doesn’t exist or update an existing record if it does. The error is because the PSCustomObject doesn’t have an add method. I would write this as a function and let the pipeline take care of adding it the the CSV.

If you replace below line

$CSV = Import-Csv $PATH


$CSV = [System.Collections.Generic.List[PSCustomObject]](Import-Csv $PATH)

it should work.

Thank you very much Daniel
works like a charm.
I’m happy.