Windows PowerShell Version 3 Simplified Syntax

Thu, 20 Oct 2011 00:44:42 +0000

Windows PowerShell version 3 introduces a simplified syntax for the Where-Object and Foreach-Object cmdlets. The simplified syntax shown below, eliminates the curly braces as well as the need for the special variable $_.

C:\PS> Get-Process | Where PM -gt 100MB ... C:\PS> Get-Process | Foreach Name ...The intent of this “syntax” is to make it easier for folks get started with PowerShell. Compared to the commands below, I can see the value of the simplified syntax:

C:\PS> Get-Process | Where {$_.PM -gt 100MB} ... C:\PS> Get-Process | Foreach {$_.Name} ...When folks are first learning PowerShell, the special variable $_ is one of those mental model hurdles they have to get over. The simplified syntax feature of V3 seems to generate a fair amount of controversy (is it really necessary, doesn"™t this just complicate things more, etc). Regardless of where you stand on the simplified syntax it is useful to understand how it works.

Given that it appears to be a simplified expression syntax you might think this required a change to the PowerShell parser"™s grammar but you would be wrong. It turns out that the simplified syntax is implemented by additional parameter sets ““ lots of additional parameter sets. In fact, for every operator supported, there is an additional parameter set to support that operator. Let”™s see this with the Where-Object cmdlet by listing out all of its parameter set names:

`C:\PS> Get-Command Where-Object | Select -Expand ParameterSets | Format-Table Name Name

```
 ~~~~~~~~~~~~~~
```

216 10 3560 2896 73 4000 atieclxx
130 7 2380 1028 33 1020 atiesrxx
157 11 17288 13344 49 7876 audiodg
28 6 1256 420 42 0.06 2752 BluetoothHeadsetProxy

Articles from October 2011 on PowerShell.org - Welcome Automaters!

Windows PowerShell Version 3 Simplified Syntax

`C:\PS> Get-Command Where-Object | Select -Expand ParameterSets | Format-Table Name Name

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