I have the following code snippet:
function MyTestString { [string]$OutString $OutString = 'ABCDEFG' #$OutString | Out-GridView -Wait -Title "String inside function" return $OutString } $MyString = MyTestString | Out-GridView -Wait -Title "Getting Extra Column"
When I run it in Powershell
, I get an extra empty column in the grid view. If Out-GridView
is placed inside the function then there is no empty column. The same thing is happening with Export-Clixml
.
How can I avoid the empty column in the grid? I would like to know why do I get an empty column in GridView
.
Here's a screen shot of the extra empty column:
Thank you for your help.
That would be extra row
instead of column, and it's caused by the function body. Let's examine it.
function MyTestString
{
[string]$OutString
$OutString = 'ABCDEFG'
return $OutString
}
MyTestString
ABCDEFG
Okay, looks like a direct call returns extra row. Is it really so?
$o=MyTestString
$o
ABCDEFG
Let's look inside $o
:
$o.GetType()
IsPublic IsSerial Name BaseType
-------- -------- ---- --------
True True Object[] System.Array
Now we are getting somewhere. The function returns an array. How about its contents?
PS C:\> $o[0]
PS C:\> $o[1]
ABCDEFG
The zeroth element doesn't contain anything but emptiness. This looks strange, so let's make sure Powershell is using strict mode (which it doesn't do per default. And that is a brain-dead a design decision.)
Set-StrictMode -Version 'latest'
MyTestString
The variable '$OutString' cannot be retrieved because it has not been set.
At line:3 char:13
+ [string]$OutString
+ ~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (OutString:String) [],
RuntimeException
+ FullyQualifiedErrorId : VariableIsUndefined
Let's see the function body again:
{
[string]$OutString
$OutString = 'ABCDEFG'
#$OutString | Out-GridView -Wait -Title "String inside function"
return $OutString
}
Note the [string]
part? That isn't a varaible declaration. It will return its contents to the pipeline. When Powershell isn't in strict mode, it returns a big fat of nothing - the empty element at $o[0]
. When in strict mode, Powershell notes that an uninitialized variable is being accessed.
As for a fix, assign a value to OutString
- unless you were trying to work with parameters.
function MyTestString
{
[string]$OutString = 'ABCDEFG'
return $OutString
}
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