PowerShell: Function doesn't have proper return value

I've found the answer here: http://martinzugec.blogspot.hu/2008/08/returning-values-from-fuctions-in.html

Functions like this:

Function bar { [System.Collections.ArrayList]$MyVariable = @() $MyVariable.Add("a") $MyVariable.Add("b") Return $MyVariable}

uses a PowerShell way of returning objects: @(0,1,"a","b") and not @("a","b")

To make this function work as expected, you will need to redirect output to null:

Function bar { [System.Collections.ArrayList]$MyVariable = @() $MyVariable.Add("a") | Out-Null $MyVariable.Add("b") | Out-Null Return $MyVariable}

In our case, the function has to be refactored as suggested by Koliat.

An alternative to adding Out-Null after every command but the last is doing this:

$i = (Test-Diff $Dir1 $Dir2 | select -last 1)

PowerShell functions always return the result of all the commands executed in the function as an Object[] (unless you pipe the command to Out-Null or store the result in a variable), but the expression following the return statement is always the last one, and can be extracted with select -last 1.

I have modified the bit of your script, to make it run the way you want it. I'm not exactly sure you would want to compare files only by the .Count property though, but its not within the scope of this question. If that wasn't what you were looking after, please comment and I'll try to edit this answer. Basically from what I understand you wanted to run a condition check after the function, while it can be easily implemented inside the function.

$Dir1 ="C:\Dir1"$Dir2 ="C:\Users\a.pawlak\Desktop\Dir2"function Test-Diff($Dir1,$Dir2){$fileList1 = Get-ChildItem $Dir1 -Recurse | Where-Object {!$_.PsIsContainer} | Get-Item | Sort-Object -Property Name$fileList2 = Get-ChildItem $Dir2 -Recurse | Where-Object {!$_.PsIsContainer} | Get-Item | Sort-Object -Property Nameif ($fileList1.Count -ne $fileList2.Count){Write-Host "Following files are different:"Compare-Object -ReferenceObject $fileList1 -DifferenceObject $fileList2 -Property FullName -PassThru | Format-Table FullNameWrite-Host "Test FAILED" -BackgroundColor Red}else { return $trueWrite-Output "Test OK" }}Test-Diff $Dir1 $Dir2

If there is anything unclear, let me know

AlexP