Compare-object doesn't seem to work with Arrays

I think I'm doing this right... Any ideas?

PS C:\Toolbox\Scripts\DNSCheck> $t
TLD5.ULTRADNS.INFO
TLD6.ULTRADNS.CO.UK
TLD1.ULTRADNS.NET
TLD2.ULTRADNS.NET
TLD3.ULTRADNS.org
TLD4.ULTRADNS.org
PS C:\Toolbox\Scripts\DNSCheck> $v
TLD4.ULTRADNS.org
TLD5.ULTRADNS.INFO
TLD6.ULTRADNS.CO.UK
TLD1.ULTRADNS.NET
TLD2.ULTRADNS.NET
TLD3.ULTRADNS.org
PS C:\Toolbox\Scripts\DNSCheck> compare-object -ref $t -diff $v
Compare-Object : Cannot bind argument to parameter 'ReferenceObject' because
it is null.
At line:1 char:20
+ compare-object -ref <<<< $t -diff $v
PS C:\Toolbox\Scripts\DNSCheck>

Actually - after doing some testing it looks like there is a problem with the
way I created my arrays (they don't appear to be arrays).

Here is the behavior I expected to see:

PS C:\Toolbox\Scripts\DNSCheck> $a = @(1,2,3,4)
PS C:\Toolbox\Scripts\DNSCheck> $b = @(1,4)
PS C:\Toolbox\Scripts\DNSCheck> compare-object $a $b

InputObject SideIndicator
----------- -------------
2 <=
3 <=

Now I just need to figure out what's wrong with my arrays...

-Chris

"Chris Harris" wrote:

> I think I'm doing this right... Any ideas?
>
> PS C:\Toolbox\Scripts\DNSCheck> $t
> TLD5.ULTRADNS.INFO
> TLD6.ULTRADNS.CO.UK
> TLD1.ULTRADNS.NET
> TLD2.ULTRADNS.NET
> TLD3.ULTRADNS.org
> TLD4.ULTRADNS.org
> PS C:\Toolbox\Scripts\DNSCheck> $v
> TLD4.ULTRADNS.org
> TLD5.ULTRADNS.INFO
> TLD6.ULTRADNS.CO.UK
> TLD1.ULTRADNS.NET
> TLD2.ULTRADNS.NET
> TLD3.ULTRADNS.org
> PS C:\Toolbox\Scripts\DNSCheck> compare-object -ref $t -diff $v
> Compare-Object : Cannot bind argument to parameter 'ReferenceObject' because
> it is null.
> At line:1 char:20
> + compare-object -ref <<<< $t -diff $v
> PS C:\Toolbox\Scripts\DNSCheck>

Chris Harris wrote:
> Actually - after doing some testing it looks like there is a problem with the
> way I created my arrays (they don't appear to be arrays).
>
> Here is the behavior I expected to see:
>
> PS C:\Toolbox\Scripts\DNSCheck> $a = @(1,2,3,4)
> PS C:\Toolbox\Scripts\DNSCheck> $b = @(1,4)
> PS C:\Toolbox\Scripts\DNSCheck> compare-object $a $b
>
> InputObject SideIndicator
> ----------- -------------
> 2 <=
> 3 <=
>
> Now I just need to figure out what's wrong with my arrays...

Using the gettype method will allow you to see what kind of object it is.

15# $a=5
16# $a.gettype()

IsPublic IsSerial Name BaseType
-------- -------- ---- --------
True True Int32 System.ValueType


17#

"Chris Harris" <ChrisHarris@discussions.microsoft.com> wrote in message
news:571754BB-E59B-489E-9584-A20C36D98CF2@microsoft.com...
> Actually - after doing some testing it looks like there is a problem with
> the
> way I created my arrays (they don't appear to be arrays).
>
> Here is the behavior I expected to see:
>
> PS C:\Toolbox\Scripts\DNSCheck> $a = @(1,2,3,4)
> PS C:\Toolbox\Scripts\DNSCheck> $b = @(1,4)
> PS C:\Toolbox\Scripts\DNSCheck> compare-object $a $b
>
> InputObject SideIndicator
> ----------- -------------
> 2 <=
> 3 <=
>
> Now I just need to figure out what's wrong with my arrays...

What you are actually trying to reproduce is this:

PS> $a=@(1,4)
PS> $b=@(4,1)
PS> compare-object $a $b
PS>

As you can see, compare-object does not capture differences such as similar
values sorted differently in an array. So if you want to identify sort
differences between $t and $v you will have to write your own comparison
routine. That shouldn't be too difficult though. A very basic example to get
you started:

PS> for ($i=0;$i -lt [System.Math]::Max($t.length,$v.length);$i++) {
>> if ($t[$i] -ne $v[$i]) {"$i : $($t[$i]) <> $($v[$i])"}
>> }
>>
0 : TLD5.ULTRADNS.INFO <> TLD4.ULTRADNS.org
1 : TLD6.ULTRADNS.CO.UK <> TLD5.ULTRADNS.INFO
2 : TLD1.ULTRADNS.NET <> TLD6.ULTRADNS.CO.UK
3 : TLD2.ULTRADNS.NET <> TLD1.ULTRADNS.NET
4 : TLD3.ULTRADNS.org <> TLD2.ULTRADNS.NET
5 : TLD4.ULTRADNS.org <> TLD3.ULTRADNS.org

Hope that helps,
Jacques

Hi Jacques - thanks for the reply.

I'm not concerned about the sorting issues because I'm sorting the arrays
before comparing them. What I'm concerned about is one array having
more/less/different entries than the other.

Here I have a hashtable where the values are arrays.

Name Value
---- -----
ns2.microsage.net {bbns.blackbaud.com, bbns2.blackbaud.com}
ns1.microsage.net



On a side note, does anyone know what's going on in the example below?

PS C:\Toolbox\Scripts\DNSCheck> $a = @("ns1.microsage.net",
"ns2.microsage.net")
PS C:\Toolbox\Scripts\DNSCheck> $b = @("ns1.microsage.net")
PS C:\Toolbox\Scripts\DNSCheck> $a -eq $b
ns1.microsage.net
PS C:\Toolbox\Scripts\DNSCheck> $a -ne $b
ns2.microsage.net
PS C:\Toolbox\Scripts\DNSCheck>
PS C:\Toolbox\Scripts\DNSCheck> $b = $a
PS C:\Toolbox\Scripts\DNSCheck> $a
ns1.microsage.net
ns2.microsage.net
PS C:\Toolbox\Scripts\DNSCheck> $b
ns1.microsage.net
ns2.microsage.net
PS C:\Toolbox\Scripts\DNSCheck> $a -eq $b
PS C:\Toolbox\Scripts\DNSCheck> $a -ne $b
ns1.microsage.net
ns2.microsage.net


Thanks,
Chris


"Jacques Barathon [MS]" wrote:

> "Chris Harris" <ChrisHarris@discussions.microsoft.com> wrote in message
> news:571754BB-E59B-489E-9584-A20C36D98CF2@microsoft.com...
> > Actually - after doing some testing it looks like there is a problem with
> > the
> > way I created my arrays (they don't appear to be arrays).
> >
> > Here is the behavior I expected to see:
> >
> > PS C:\Toolbox\Scripts\DNSCheck> $a = @(1,2,3,4)
> > PS C:\Toolbox\Scripts\DNSCheck> $b = @(1,4)
> > PS C:\Toolbox\Scripts\DNSCheck> compare-object $a $b
> >
> > InputObject SideIndicator
> > ----------- -------------
> > 2 <=
> > 3 <=
> >
> > Now I just need to figure out what's wrong with my arrays...
>
> What you are actually trying to reproduce is this:
>
> PS> $a=@(1,4)
> PS> $b=@(4,1)
> PS> compare-object $a $b
> PS>
>
> As you can see, compare-object does not capture differences such as similar
> values sorted differently in an array. So if you want to identify sort
> differences between $t and $v you will have to write your own comparison
> routine. That shouldn't be too difficult though. A very basic example to get
> you started:
>
> PS> for ($i=0;$i -lt [System.Math]::Max($t.length,$v.length);$i++) {
> >> if ($t[$i] -ne $v[$i]) {"$i : $($t[$i]) <> $($v[$i])"}
> >> }
> >>
> 0 : TLD5.ULTRADNS.INFO <> TLD4.ULTRADNS.org
> 1 : TLD6.ULTRADNS.CO.UK <> TLD5.ULTRADNS.INFO
> 2 : TLD1.ULTRADNS.NET <> TLD6.ULTRADNS.CO.UK
> 3 : TLD2.ULTRADNS.NET <> TLD1.ULTRADNS.NET
> 4 : TLD3.ULTRADNS.org <> TLD2.ULTRADNS.NET
> 5 : TLD4.ULTRADNS.org <> TLD3.ULTRADNS.org
>
> Hope that helps,
> Jacques
>
>