What does $_ mean in PowerShell?

Micah_17744 0
Viewed 301349

I've seen the following a lot in PowerShell, but what does it do exactly?

$_
powershell
7 Answers

The $_ is a $PSItem, which is essentially an object piped from another command. For example, running Get-Volume on my workstations returns Rows of PSItems, or objects

get-volume | select driveLetter,DriveType   

driveLetter DriveType
----------- ---------
      D      Fixed
             Fixed
      C      Fixed
      A      Removable

Driveletter and DriveType are properties Now, you can use these item properties when piping the output with $_.(propertyName). (Also remember % is alias for Foreach-Object) For example

$vol = get-volume | select driveLetter,DriveType

$vol | Foreach-Object {
    if($_.DriveType -eq "Fixed") {
        "$($_.driveLetter) is $($_.driveType)"}
     else{
        "$($_.driveLetter) is $($_.driveType)"
     }
 }

Using Terinary in Powershell 7, I am able to shorten the logic while using properties from the Piped PSItem

user_166552900
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