powershell returns System.Object[] instead of given value

Question

I made a small script that passes makes a site based on a template:

Function CreateSite($parentUrl, $SubSiteUrl, $Template, $Title) {
try {
    write-host "init"    
    $site = New-Object -Type Microsoft.SharePoint.SPSite -ArgumentList $parentUrl
    write-host "load web"
    $web = $site.OpenWeb()
    write-host "reading template"
    $wtemplate = $web.GetAvailableWebTemplates(1033) | Where-Object {$_.Name -eq $Template}
    $url = $parentUrl + "/" + $SubSiteUrl
    write-host "creating site"
    New-SPWeb -Url $url -Name $Title -UseParentTopNav
    $web = GET-SPWeb $url
    write-host "applying template"
    $web.ApplyWebTemplate($Template)
    write-host "done"
    return "OK"

}
            catch {
            $ErrorMessage = $_.Exception.Message
            write-host $ErrorMessage
            return ($ErrorMessage)
}

The parameters are provided in a list, and in the calling function I write the output of the function back to the list. This works with all of my other functions, except this one. I call it like:

$message = CreateSite -parenturl $url.Url -SubSiteUrl $SubSiteUrl -Template $Template -Title $Title

During debug, I can see that the function returns this:

$message=
Url
---
https://... (here comes the full url of the site i just made)
OK

In the log list I only see System.Object[] as output. I expect only OK to be returned. This looks like a common problem, but only related to arrays, and here I only return a static value. Can someone give me a hint?

Answer 1

As discussed in the comments, New-SPWeb has a return value. Set it in a variable or pipe it into Out-Null.

$NewWeb = New-SPWeb -Url $url -Name $Title -UseParentTopNav

Or

New-SPWeb -Url $url -Name $Title -UseParentTopNav | Out-Null

https://technet.microsoft.com/en-us/library/ff607579.aspx