Sorting and Comparing Arraylists - powershell

Question

I'm pretty new to Powershell and have a problem.
It seems I can get neither the Compare-Object nor the Sort-Object funtions to work.
I got two Arraylists which I fill with 10 objects of type "Table".
#Create Arraylists
$list1 = new-object System.Collections.ArrayList
$list2 = new-object System.Collections.ArrayList
#Declare Table-Class
class Table {
[String] $name
[Int] $number
}
#Fill list1
[Int] $i = 0
while ($i -lt 10) {
$entry = new-Object Table
$entry.name = "Name";
$entry.number = $i;
$list1.Add($entry)
$i++
}
#Fill list2
[Int] $j = 10
while ($j -gt 0) {
$entry = new-Object Table
$entry.name = "name";
$entry.number = $j;
$list2.Add($entry)
$j--
}
Now I want to compare these two ArrayLists like this:
Compare-Object $list1 $list2 | ForEach-Object {$_.InputObject}
This doesn't seem to work and I think it's because I'm not really doing anything with the comparison. If someone could help me with the correct Syntax I'd be really happy.
Anyway, I think this comparison would somehow return a $false boolean.
If that were true, I'd like to sort $list2 by $entry.number.
I'm attempting this like that:
$list2 = $list2 | Sort-Object -Property { $_[1] }
But my list doesn't change at all. I already tried several different "solutions" but it seems none of these is a real "solution".
I'd be really glad if someone could help me or at least point me in the right direction.
EDIT: For future readers, here is the working syntax:
#sort list by the property number
$list2 = $list2 | sort-object -Property number
#count differences and if differences greater than 0, do stuff
[Int] $diff
$properties = $list1 | Get-Member -MemberType Property | Select-Object -ExpandProperty Name
foreach ($property in $properties) {
$diff = 0
$diff = (Compare-Object $list1 $list2 -Property "$property").count
if ($diff -ne 0) {
#do stuff
}
else {
#do something else
}
}

Answer 1

Your sorting does not work because -Property expects you to pass the name of an actual property. In your case the class two properties: $name and $number. You can also check what properties an object has by using $list2 | Get-Member. So in order to sort, you can use:
$list2 = $list2 | Sort-Object -Property number
Now the reason Compare-Object is not working is because it's implemented differently that one might expect. See this answer explaining how it works.
One other thing you should keep in mind: Calling $list2.Add($entry) actually returns an integer (the index of the inserted element). PowerShell returns all uncaptured output. This can cause some unexpected behavior/output if you are not careful. So you should get in the habit of writing [void] $list2.Add($entry), unless you really want to return those indexes.