PowerShell wait for output from function or invoke-command - powershell

Question

I have a script block/function that returns PSCustomObject followed by Write-Host.
I want to get the output first then print the write-host but I can't seem to figure it out.
function ReturnArrayList {
param (
[int] $number
)
[System.Collections.ArrayList]$folderList = #()
$folderObject = [PSCustomObject]#{
Name = 'John'
number = $number
}
#Add the object to the array
$folderList.Add($folderObject) | Out-Null
return $folderList
}
$sb = {
param (
[int] $number
)
[System.Collections.ArrayList]$folderList = #()
$folderObject = [PSCustomObject]#{
Name = 'John'
number = $number
}
#Add the object to the array
$folderList.Add($folderObject) | Out-Null
return $folderList
}
ReturnArrayList -number 5
#Invoke-Command -ScriptBlock $sb -ArgumentList 5
Write-Host "This write host should come later"
Result:
This write host should come after
Name number
---- ------
John 5
Desired result:
Name number
---- ------
John 5
This write host should come after
How can I get the return result first and print the write-host message?
Thank you for your help in advance!

Answer 1

You can force PowerShell to write the output from ReturnArrayList to the screen before reaching Write-Host by piping it to either one of the Format-* cmdlets or Out-Default:
$object = ReturnArrayList -number 5
$object |Out-Default
Write-Host "This write host should come later"
Result:
Name number
---- ------
John 5
This write host should come later
Beware that your ReturnArrayList function does not actually return an ArrayList - PowerShell will automatically enumerate the item(s) in $folderlist, and since it only contains one item, the result is just a single PSCustomObject, "unwrapped" from the ArrayList so to speak:
PS ~> $object = ReturnArrayList -number 5
PS ~> $object.GetType().Name
PSCustomObject
To preserve enumerable types as output from functions, you'll need to either use Write-Output -NoEnumerate, or wrap the it in an array using the , operator:
function ReturnArrayList {
param (
[int] $number
)
[System.Collections.ArrayList]$folderList = #()
$folderObject = [PSCustomObject]#{
Name = 'John'
number = $number
}
#Add the object to the array
$folderList.Add($folderObject) | Out-Null
return ,$folderList
# or
Write-Output $folderList -NoEnumerate
}

Answer 2

Data is usually output to the pipeline, while Write-Host bypasses the pipeline and writes to the console directly.
Using Write-Output instead of Write-Host will fix this issue. You can easily find more in-depth information on this topic, and when not to Write-Host.