Scripting Games Comments VIII: Creating Objects
One thing we have to do quite frequently is create an object and populate some variables. In PowerShell v1 we would do something like this
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| $r = Get-WmiObject -Class Win32_OperatingSystem
$system = New-Object System.Management.Automation.PSObject
Add-Member -InputObject $system -MemberType Noteproperty -Name SystemDevice -Value $r.SystemDevice
Add-Member -InputObject $system -MemberType Noteproperty -Name SystemDrive -Value $r.SystemDrive
Add-Member -InputObject $system -MemberType Noteproperty -Name SystemDirectory -Value $r.SystemDirectory
$system |
We get some data – in this case from WMI
We use New-Object to create an object – I’ve used the full type name deliberately
$system = New-Object PSObject
works just as well.
Add-Member is used to add three NoteProperties and then we display the object to get
SystemDevice SystemDrive SystemDirectory
------------ ----------- ---------------
\Device\HarddiskVolume2 C: C:\Windows\system32
Its a bit of a contrived example but it works.
It is possible to make this a bit easier and less typing
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| $r = Get-WmiObject -Class Win32_OperatingSystem
$system = New-Object System.Management.Automation.PSObject
$system | Add-Member -MemberType Noteproperty -Name SystemDevice -Value $r.SystemDevice -PassThru |
Add-Member -MemberType Noteproperty -Name SystemDrive -Value $r.SystemDrive -PassThru |
Add-Member -MemberType Noteproperty -Name SystemDirectory -Value $r.SystemDirectory
$system |
Add-Member has a –PassThru parameter that enables us to pipeline the property creations.
PowerShell v2 makes it even easier
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| $r = Get-WmiObject -Class Win32_OperatingSystem
$system = New-Object System.Management.Automation.PSObject -Property @{
SystemDevice = $r.SystemDevice
SystemDrive = $r.SystemDrive
SystemDirectory = $r.SystemDirectory
}
$system |
New-Object does all the work for us – it even creates each property as a NoteProperty. All we do is give the property information as a hash table. If you want this all on one line then separate each pair by a semi-colon “;”