How to remove an object from a JSON file in PowerShell - json

Question

I am trying to remove an object from a JSON file using PowerShell.
I read in a JSON file that has some objects in it (C:\eventStaging.json = [{"server_name":"server1","date":"2021-08-13","user":"user1"},{"server_name":"server2","date":"2021-08-13","user":"user2"}] )
The plan is to loop through each object, add that object to another json file (C:\scheduledEvent.json) and then remove that same object from where it came from (C:\eventStaging.json).
Adding each object to a different json file is easy enough. Here is what I have:
$json = Get-Content 'C:\eventStaging.json' | Out-String | ConvertFrom-Json
foreach ($j in $json){
$EventStart = Get-Content 'C:\scheduledEventStart.json' | Out-String | ConvertFrom-Json
$eventStartList += $EventStart
$eventStartList += $j
$eventStartList | ConvertTo-Json -depth 100 | Out-File 'C:\scheduledEventStart.json'
}
My problem is removing the object $j from eventStaging.json.
I have tried:
$removeStaging = Get-Content 'C:\eventStaging.json' | Out-String | ConvertFrom-Json
$removeStaging.PSObject.Properties.Remove($j)
$removeStaging | ConvertTo-Json -depth 100 | Out-File 'C:\eventStaging.json' -Force
but $removeStaging is storing nothing.
I also tried:
[System.Collections.ArrayList]$removeStaging = Get-Content 'C:\eventStaging.json' | Out-String | ConvertFrom-Json
$newStaging = $removeStaging.Remove($j)
$newStaging | ConvertTo-Json -depth 100 | Out-File 'C:\eventStaging.json'
but again, $newStaging stores nothing..
Has anyone any guidance on this please?

Answer 1

If you have access to PowerShell Core, you can use ConvertFrom-Json -AsHashTable when removing the scheduled event from eventStaging.json to make this a bit easier:
$removeStaging = Get-Content -Raw 'C:\eventStaging.json' | ConvertFrom-Json -AsHashTable
$removeStaging.Remove($j)
$removeStaging | ConvertTo-Json -depth 100 | Out-File 'C:\eventStaging.json' -Force
With Windows PowerShell, your final attempt with the ArrayList conversion should have worked, assuming you are trying to remove a top-level element and not a sub-property of the element. Testing with the following code shows my json file is updated with the removed element:
# Create test json file
#{Name = 'Bender'; Age = 99}, #{Name = 'Dean'; Age = 98} | ConvertTo-Json | Out-File test.json
# Import JSON as ArrayList of PSCustomObjects
[System.Collections.ArrayList]$obj = Get-Content -Raw test.json | ConvertFrom-Json
# Remove one of the objects by reference
$obj.Remove($obj[1])
# Write the JSON to file, it will only have the one entry in it
$obj | ConvertTo-Json | Out-File test.json
If you update your question with a more complete sample of this area I can evaluate further but either of the above approaches should work.
Additionally, note I've removed your use of Out-String and instead used Get-Content -Raw. The -Raw parameter tells Get-Content to parse the file as a literal string instead of returning a collection of single-lines.