Sometimes you’ll need a means to filter out everything you don’t need when working with property values of Windows Powershell in a set of objects. This is when the Powershell Where-Object comes in handy. Don’t know how to use this command? This guide will teach you how.

What Is Powershell Where-Object?

The cmdlet Where-Object in Windows PowerShell is designed solely to filter the command’s output and give back particular data that users wish to print. In short, this cmdlet is a type of filter, allowing you to create a condition that only produces either False or True. It either gives back the result or not, depending on the situation.

You have two options for creating this condition: parameter and script blocks.

Use Powershell Script Blocks To Create The Filter Condition

In PowerShell, script blocks are one crucial element. These are employed in countless places in the script language. The script block is a type of anonymous function which organizes code and runs it in several locations.

Below is an example of a script block to help you better understand.

{$_.StartType -EQ 'Automatic'}

Utilizing the Powershell pipeline, users may pipe the items to the cmdlet Where-Object and utilize the parameter FilterScript. Given that FilterScript takes script blocks, you can establish a condition to determine if each object’s property equals a particular value.

Here is a sample.

Get-Service | Where-Object -FilterScript {$_.StartType -eq 'Automatic'}

Notice that you may utilize the cmdlet Where-Object with positional parameters and not include the name of the parameter FilterScript. For a quicker and clearer approach of scripting, you instead offer a script block by itself, such as Where-Object {$_.StartType -eq ‘Automatic’}.

Although this particular syntax is effective in this situation, the idea of script blocks with curly braces {} will make the code harder to read and understand for Windows PowerShell beginners. This problem of readability made the Powershell team introduce the parameters.

Use Powershell Parameter To Create The Filter Condition

Since PowerShell 3.0, the parameters now have a more natural writing style. Let’s utilize parameters to filter certain outputs in the same example as before.

Here is the sample code.

Get-Service | Where-Object -Property StartType -eq 'Automatic'

As you can see above, the property of the object is specified by the command as one parameter value to the Property parameter rather than utilizing a script block. Additionally, the operator -eq is a parameter, enabling you to send the value Automatic to it.

A script block is no longer required when utilizing parameters. Still, even if Microsoft offered parameters as a simpler form of scripting, there are many benefits to using script blocks.

Utilize Multiple Conditional Statements

With script blocks, you may combine and evaluate more than two conditions using an operator (such as –or or –and). Still, in order to effectively assess each condition, you must employ a specific PowerShell feature called subexpressions.

Subexpressions may be used to execute an expression inside of a filter syntax such as Where-Object. To accomplish this, enclose conditional statements you are running in parenthesis ().

Below is a sample code.

Get-Process | Where-Object {($_.CPU -gt 2.0) -and ($_.CPU -lt 10)}

Here is an example of the script block.

Handles  NPM(K)    PM(K)      WS(K)     CPU(s)     Id  SI ProcessName
-------  ------    -----      -----     ------     --  -- -----------
    334      21    18972      26384       5.23   3808   0 AnyDesk
    635      34    13304      51264       9.56   4140   5 notepad
    726      36    12820      51196       4.69  12088   5 notepad
    802      46    18356      65088       7.98  10784   5 OneDrive
    340      18     6472      26436       3.44   1252   5 RuntimeBroker
    698      34    14672      44484       3.63   3284   5 RuntimeBroker
    323      19     5732      23432       4.00  11200   5 RuntimeBroker
    560      18     6440      27752       4.63   8644   5 sihost
    632      31    21524      69972       2.81   6392   5 StartMenuExperienceHost
    390      18     9756      30832       3.94   3084   5 svchost
    523      24     8768      36312       2.17   6300   5 svchost
    524      17     6416      21036       4.42  10932   5 SynTPEnh
    525      22    15336      38904       3.41   2192   5 TextInputHost

The Bottom Line

Now you know how to utilize Powershell Where-Object. Hopefully, you will find this guide easy to understand and follow.In case you aren’t familiar with the commands in Powershell, maybe you should start with this guide on the cmdlet Start Process. This command is quite useful when working with this language scripting.