PowerShell : resolving error – Method invocation failed because [System.Management.Automation.PSObject] does not contain a method named ‘op_Addition’

Hi All,

Greetings for the day!!!

Today, a new issue and solution ! This is common or simple issue, but since it took a bit time to solve, I thought to share it.

Issue – Method invocation failed because [System.Management.Automation.PSObject] does not contain a method named ‘op_Addition’

Details

• I have written a PowerShell script to get all apps installed on my site collection.
• I am preparing array objects with app values which I want to export to CSV file.
• Below is sample code:

#preparing PowerShell array object to hold the app instance data
    $AppData += New-Object PSObject -Property @{
        'App ID' = $appTile.AppId
        'App Source' = $appTile.AppSource
        'App Status' = $appTile.AppStatus
        'App Type' = $appTile.AppType
        'App Title' = $appTile.Title -join ""
   }#$AppData

   #writing app data to CSV file
   $AppData | Out-File $allApps_CSV -Append

Issue

• While executing the PowerShell script, I am getting the following error:

Method invocation failed because [System.Management.Automation.PSObject] does not contain a method named ‘op_Addition’.
At C:\Prasham\Articles\PowerShell\getallappsinstalled_V1_Kj.ps1:23 char:5

• $AppData += New-Object PSObject -Property @{
• ~~~~~~~~~~~~
  • CategoryInfo : InvalidOperation: (op_Addition:String) [], RuntimeException
  • FullyQualifiedErrorId : MethodNotFound

Solution / Cause of an error

• It seems like a simple solution. But from the error, it was not easily understood.
• The cause of an issue is that the array object which we are using is not declared. We need to declare the array object as

#result array declaration
$AppData = @()

• As I declared the array, script executed like a charm.

HAPPY SHARING !!! HAPPY LEARNING!!! HAVE a FANTASTIC TIME AHEAD !!!