Powershell variable contains the value twice - powershell

Question

I have a powershell script that is started bij a jenskinsfile. This all works well. But in the script I have a function to download a file. This does not work, because the $filePath variable contains the value twice. When this part would be run the log would look like:
https://example.com/api/download
D:\folder\file_2.txt D:\folder\file_2.txt
How can I get the value only to be there ones in $filePath ?
function DownloadFile ($folder, $version) {
$wc = New-Object System.Net.WebClient
$wc.Headers['Content-Type'] = 'application/json'
$requesturl = "https://example.com/api/download"
$filePath = Join-Path -Path $folder -ChildPath "\file_$version.txt"
Write-Host "$requesturl"
Write-Host "$filePath"
$wc.DownloadFile($requesturl, $filePath)
return $filePath
}

Answer 1

The implication is that the argument you're passing to the -folder parameter (as represented inside your function as the $folder parameter variable) is an array of folder paths, not a single one.
The solution is therefore to make sure that you only pass a single folder path when you call your DownloadFile function; e.g.:
DownloadFile -folder D:\folder -version 2
# With *positional* parameter binding:
DownloadFile D:\folder 2
Since Join-Path accepts an array of paths as a -Path argument, it outputs multiple paths when given an array; e.g.:
PS> $folder = 'c:\abc', 'c:\def'; Join-Path -Path $folder -ChildPath file.txt
c:\abc\file.txt
c:\def\file.txt
Passing an array Write-Host implicitly stringifies it, which means creating a single string composed of the array elements joined with spaces:
PS> $folder = 'c:\abc', 'c:\def'; Write-Host $folder
c:\abc c:\def
(Note that this differs from implicit output / output via Write-Output, which prints each array element on its own line; also, implicit output / Write-Output write to the pipeline, meaning they output data for later processing, whereas Write-Host writes strings to the display).