PowerShell hash-table return values

Question

I have a simple script to return values from a hash table:

param
(
    [Parameter(Mandatory = $true)]
    [string]$Name
)

function getvalues ($Name) {

    $nameList= @{"CFT"=@{"name1"="text1"; "name2"="text2"}}

    #return $nameList[$Name]
    return ,$nameList
}

$Values = getvalues($Name)

    Write-Debug "DEBUG: Name1     = "$Values["name1"]
    Write-Debug "DEBUG: Name2     = "$Values["name2"]

When I run it, I get the following error:

Write-Debug : A positional parameter cannot be found that accepts argument '$null'.
At C:\MSFT\add-test.ps1:21 char:2
+     write-Debug "DEBUG: Name1     = "$Values["name1"]
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (:) [Write-Debug], ParameterBindingException
    + FullyQualifiedErrorId : PositionalParameterNotFound,Microsoft.PowerShell.Commands.WriteDebugCommand

Write-Debug : A positional parameter cannot be found that accepts argument '$null'.
At C:\MSFT\add-test.ps1:22 char:2
+     write-Debug "DEBUG: Name2     = "$Values["name2"]
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (:) [Write-Debug], ParameterBindingException
    + FullyQualifiedErrorId : PositionalParameterNotFound,Microsoft.PowerShell.Commands.WriteDebugCommand

Answer 1

You're terminating your strings and then using the $Values lookup. Either use a + or embed it into the string, or use the -f operator:

write-Debug ("DEBUG: Name1   = " + $Values["name1"])
write-Debug "DEBUG: Name2   = $($Values["name2"])"
write-Debug ("DEBUG: Name3   = {0}" -f $Values["name3"])

Note forms 1 and 3 need parentheses ( ).

Regarding your comment that there are no more errors and no output:

Are you sure your debug preference is set such that you can see the output? The point of Write-Debug and Write-Verbose is that you only see the output when the preference is set as such (and you shouldn't add DEBUG: in your string, it will be added for you). I suspect Write-Verbose is more appropriate for what you're doing.

To test quickly whether it will work, you can actually add -Debug or -Verbose as appropriate.

So for example:

Write-Verbose "Name2   = $($Values["name2"])" -Verbose