How to handle $null in the pipeline

Question

I often have the following situation in my PowerShell code: I have a function or property that returns a collection of objects, or $null. If you push the results in

Answer 1

A quick note to Keith's answer to complete it

Personally, I would return nothing. It makes sense:

PS> function Empty { if ('a' -eq 'b') { 'equal' } }
PS> Empty | % { write-host result is $_ }

But now you are in problems if you assign result from Empty to a variable:

PS> $v = Empty
PS> $v | % { write-host result is $_ }

There is a little trick to make it work. Just wrap the result from Empty as a array like this:

PS> $v = @(Empty)
PS> $v | % { write-host result is $_ }
PS> $v.GetType()
IsPublic IsSerial Name      BaseType
-------- -------- ----      --------
True     True     Object[]  System.Array
PS> $v.Length
0