Simple script to ping PCs, output table - what's wrong? - powershell

Question

I was trying to write a simple script to ping a list of computers, and output the result in a table. I ended up doing this, which works fine:
Get-ADComputer -searchbase "OU=Materials,OU=MMC Computers,OU=REI,DC=REIDOMAIN,DC=LOCAL" -filter * | select -expand name | % {
$output = New-Object PSObject
$output | Add-Member NoteProperty "Computer name"($_)
$output | Add-Member NoteProperty "Ping result"("$($(Test-Connection $_ -count 1 -quiet).ToString())")
write $output }
However, I'd like to understand why my first two attempts didn't work, so that I can avoid making the same mistakes later. Here they are:
Script 1: See edit below
Get-ADComputer -searchbase "OU=Materials,OU=MMC Computers,OU=REI,DC=REIDOMAIN,DC=LOCAL" -filter * |
select -expand name | % { $computer = $_; $obj = "" |
select #{Name="Computer";Expression="$computer"},`
#{Name="Pingable";Expression="$($(Test-Connection $computer -count 1 -quiet).ToString())"}
$obj }
Output 1:
Computer Pingable
-----— -----—
Note: Under the table headers, this script actually prints one blank line for each computer I'm pinging.
Script 2:
$table = #{Expression={$_};Label="Computer"},#{Expression={"$($(Test-Connection $_ -count 1 -quiet).ToString())"};Label="Pingable"}
Get-ADComputer -searchbase "OU=Materials,OU=MMC Computers,OU=REI,DC=REIDOMAIN,DC=LOCAL" -filter * | select -expand name | format-table $table
Output 2:
mickeymouse
goofy
minnie
pluto
frank
This one doesn't even output a table...it just prints one computer name per line.
I'd appreciate if someone could explain what's going wrong in these two attempts. Thanks!
Edit: Got Script 1 to work.
Get-ADComputer -searchbase "OU=Materials,OU=MMC Computers,OU=REI,DC=REIDOMAIN,DC=LOCAL" -filter * |
select #{Name="Computer";Expression={$_.Name}},#{Name="Pingable";Expression={"$($(Test-Connection $_.Name -count 1 -quiet).ToString())"}};
Still curious about Script 2

Answer 1

In your second example, you are using the -ExpandProperty of Select-Object which effectively strips the data from the object and outputs an array of strings which format-table then outputs as a list.
See this example:
#First create the array of objects
$rawData = #( #{"Name"="First Obj"; "OtherParam"=1;}, #{"Name"="Second Obj"; "OtherParam"=2;})
$objects = $rawData | %{new-object -type psobject -prop $_}
#Just output the objects
$objects | format-table
Output:
Name OtherParam
---- ----------
First Obj 1
Second Obj 2
Now select the name property, this gives an array of objects with just a single property "name"
$objects | select name | format-table
Output:
Name
----
First Obj
Second Obj
Expand the name property, this gives an array of strings that format table just lists with no heading:
$objects | select -expand name | format-table
Output:
First Obj
Second Obj