Powershell function not receiving parameters - powershell

Question

I have a Powershell script. My ultimate goal is to compare the two Excel files and highlight differences in both versions. Part of my "preparatory code" is this:
function DefineVars () {
Clear-Host
# Define some basic variables
$Directory = Split-Path -Parent $PSCommandPath
$FilePath = $Directory + "\xlsx\"
$FileName1 = $FilePath + "Firewallv2.xlsx"
$FileName2 = $FilePath + "Firewallv3.xlsx"
$OutFile1 = $FilePath + "file1_raw.csv"
$OutFile2 = $FilePath + "file2_raw.csv"
# Create an Object Excel.Application using Com interface
$Excel = New-Object -ComObject Excel.Application
$Excel.Visible = $false
$Excel.DisplayAlerts = $false
# Generate the Workbook Objects
$WorkBook1 = $Excel.Workbooks.Open($FileName1)
$WorkBook2 = $Excel.Workbooks.Open($FileName2)
return $Directory, $FilePath, $FileName1, $FileName2, $OutFile1, $OutFile2, $Excel, $WorkBook1, $WorkBook2
}
function GenerateData ($WorkBook, $OutFile) {
$Results = #()
Write-Host $OutFile
foreach ($CurrentWorkSheet in $WorkBook.Worksheets) {
$CurrentWorkSheetName = $CurrentWorkSheet.Name
$CurrentWorkSheetRows = $CurrentWorkSheet.UsedRange.Rows.Count
$CurrentWorkSheetColumns = $CurrentWorkSheet.UsedRange.Columns.Count
$CurrentWorkSheet.Activate()
for ($CurrentColumn = 1; $CurrentColumn -le $CurrentWorkSheetColumns; $CurrentColumn++) {
for ($CurrentRow = 1; $CurrentRow -le $CurrentWorkSheetRows; $CurrentRow++) {
$CurrentCell = $CurrentWorksheet.Cells.Item($CurrentRow, $CurrentColumn)
$CurrentCellContent = $CurrentCell.Text
if ([System.IO.File]::Exists($OutFile)) {
Write-Host "true"
#","+$CurrentCellContent | Out-File $OutFile -Append
} else {
Write-Host "false"
#$CurrentCellContent | Out-File $OutFile
}
}
}
}
return $Results
}
function CloseExcel () {
$WorkBook1.Close($true)
$WorkBook2.Close($true)
$Excel.Quit()
spps -n Excel
}
$Directory, $FilePath, $FileName1, $FileName2, $OutFile1, $OutFile2, $Excel, $WorkBook1, $WorkBook2 = DefineVars
$ResultsFile1 = GenerateData($WorkBook1, $OutFile1)
$ResultsFile2 = GenerateData($WorkBook2, $OutFile2)
CloseExcel
My problem is that the parameter call to the GenerateData functions of the $OutFile variables won't work for some reason. All the other parameters appear to be passed successfully, e.g. the WorkBooks. But if I insert a Write-Host $OutFile at the beginning of the GenerateData function, the string is empty (which means it doesn't get passed, if I am not mistaken).
I am sure this is easily explained, but I just can't seem to figure this one out.
Thanks and best
Simon

Answer 1

I got it. My problem was the syntax in the main method. Being caught up in other languages, I thought I needed parentheses and commas to pass arguments. Yet, it's much simpler with Powershell:
$ResultsFile1 = GenerateData $WorkBook1 $OutFile1
$ResultsFile2 = GenerateData $WorkBook2 $OutFile2
CompareObjects $ResultsFile1 $ResultsFile2
CloseExcel
This did the trick! The only weird thing about it is that Powershell doesn't throw an error, if you stick to the parentheses-comma style of coding. The argument simply doesn't get passed.