CODEWITHSUNDEEP
powershell
MMAX
MMAX

Reputation: 619

Count properties of an object

I try to count the number of drives on certain VM's in a Cluster:

(Get-ClusterGroup -Cluster <Name> | 
    Where-Object {$_.GroupType –eq 'VirtualMachine'} | 
    Get-VM | 
    Measure-Object -Property Harddrives).Count

--> Returns 55, the count of VM's in the Cluster

Several VM's have more than one Harddrive, how can I retrieve the proper Count of Drives in a pipelined command?

Upvotes: 4

Views: 4526

Answers (3)

Slogmeister Extraordinaire
Slogmeister Extraordinaire

Reputation: 3181

I had a problem that was closer to the original question. I had a custom PowerShell object that I needed to literally count how many properties were in it. I found this:

($Object | Get-Member -MemberType NoteProperty | Measure-Object).Count

Upvotes: 4

Maximilian Burszley
Maximilian Burszley

Reputation: 19694

Try enumerating the property:

$harddrives = Get-ClusterGroup -Cluster '<String>' | ? GroupType -eq VirtualMachine |
        Get-VM | % HardDrives
$harddrives.Count

Some shorthand in v4+:

(@(Get-ClusterGroup -Cluster '<String>').
    Where({ $_.GroupType -eq 'VirtualMachine' }) |
    Get-VM).HardDrives.Count

Upvotes: 3

mklement0
mklement0

Reputation: 440297

To complement TheIncorrigible1's helpful answer, which contains an effective solution but only hints at the problem with your Measure-Object call:

Perhaps surprisingly, Measure-Object doesn't enumerate input objects or properties that are themselves collections, as the following examples demonstrate:

PS> ((1, 2), (3, 4) | Measure-Object).Count
2  # !! The input arrays each counted as *1* object - their elements weren't counted.

PS> ([pscustomobject] @{ prop = 1, 2 }, [pscustomobject] @{ prop = 3, 4 } | 
      Measure-Object -Property prop).Count
2  # !! The arrays stored in .prop each counted as *1* object - their elements weren't counted.

The above applies as of Windows PowerShell v5.1 / PowerShell Core v6.1.0.
This GitHub issue suggests introducing a -Recurse switch that would allow opting into enumerating collection-valued input objects / input-object properties.

Upvotes: 2

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