Programming
PowerShell Interview Questions and Answers for 2026
4.7 Rating 65 Questions 35 mins read350 Readers
Programming
4.7 Rating 65 Questions 35 mins read350 Readers
In PowerShell, a pipeline is a way to pass objects from one command to another, allowing you to chain multiple commands together. The output of one command is used as the input for the next command. This allows you to perform a series of transformations on the data as it passes through the pipeline.
An example of a simple pipeline in PowerShell:
Get-Process | Where-Object {$_.Handles -gt 1000} | Sort-Object Handles | Select-Object -First 5 This pipeline retrieves a list of processes, filters out any processes with fewer than 1000 handles, sorts the remaining processes by the number of handles, and then selects the first 5 processes in the sorted list.
Each stage of the pipeline is called a "command," and the commands are separated by the "pipe" character (|). The output of each command is passed to the next command as input.
PowerShell can be used for a wide range of tasks, including:
Some key concepts and features of PowerShell that a user should be familiar with include:
This is one of the most frequently asked PowerShell interview questions for freshers in recent times.
An overview of some basic syntax and concepts of PowerShell:
To use the help system in PowerShell, you can use the Get-Help cmdlet to display information about PowerShell cmdlets, functions, scripts, and concepts. For example, to get help for a cmdlet, you can use a command like this:
Get-Help CmdletName
Replace "CmdletName" with the name of the cmdlet that you want to learn about.
To create a custom cmdlet in PowerShell, you need to create a class that inherits from the System.Management.Automation.Cmdlet class and define the appropriate methods and parameters.
Here's an example of a simple cmdlet that multiplies two numbers:
class MultiplyNumbers : Cmdlet
{
[Parameter(Position=0)]
public int X { get; set; }
[Parameter(Position=1)]
public int Y { get; set; }
protected override void ProcessRecord()
{
WriteObject(X * Y);
}
} To use this cmdlet, you need to compile it into a dynamic-link library (DLL) and then import the DLL into your PowerShell session.
To compile the cmdlet, you can use the Add-Type cmdlet:
Add-Type -TypeDefinition @"
using System.Management.Automation;
class MultiplyNumbers : Cmdlet
{
[Parameter(Position=0)]
public int X { get; set; }
[Parameter(Position=1)]
public int Y { get; set; }
protected override void ProcessRecord()
{
WriteObject(X * Y);
}
}
"@ -OutputAssembly C:\path\to\MultiplyNumbers.dll To import the DLL into your PowerShell session, you can use the Import-Module cmdlet:
Import-Module C:\path\to\MultiplyNumbers.dll
You can then use the cmdlet like any other cmdlet:
MultiplyNumbers -X 2 -Y 3
This will output 6.
You can find more information about creating custom cmdlets in the PowerShell documentation.
The PowerShell ISE (Integrated Scripting Environment) is a graphical user interface for developing and debugging PowerShell scripts. It provides features such as syntax highlighting, code completion, and debugging tools.
To start the PowerShell ISE, you can type powershell_ise in the Start menu or run the powershell_ise.exe file from the installation directory.
In the PowerShell ISE, you can create a new script by clicking the File menu and selecting New. You can open an existing script by clicking the File menu and selecting Open.
To run a script, you can press F5 or click the Debug menu and select Start Debugging.
To set a breakpoint in a script, you can click in the margin to the left of the line of code or press F9. You can then use the Debug menu or the debugging toolbar to step through the code, examine variables, and perform other debugging tasks.
You can find more information about the PowerShell ISE in the PowerShell documentation.
Don't be surprised if this question pops up as one of the top PowerShell interview questions in your next interview.
Regular expressions are a powerful tool for pattern matching and text manipulation. You can use regular expressions in PowerShell by using the -match operator or the Select-String cmdlet.
Here's an example of using the -match operator to check if a string matches a regular expression:
$string = "Hello, world!"
if ($string -match "world") {
Write-Output "The string contains the word 'world'."
} Here's an example of using the Select-String cmdlet to extract all the words that start with the letter "s" from a string:
$string = "This is a test string."
$matches = Select-String -InputObject $string -Pattern "\bs\w*" -AllMatches
foreach ($match in $matches.Matches) {
Write-Output $match.Value
} This will output "string".
You can find more information about using regular expressions in PowerShell in the PowerShell documentation or by using the Get-Help cmdlet. For example:
Get-Help about_Regular_Expressions
This, along with other interview questions on PowerShell for freshers, is a regular feature in PowerShell interviews, be ready to tackle it with the approach mentioned below.
The PowerShell pipeline allows you to chain cmdlets together, passing the output of one cmdlet as the input to another cmdlet. This allows you to create complex command lines by combining simple commands.
To use the pipeline, you use the | (pipe) character to separate cmdlets. The output of the first cmdlet is passed as the input to the second cmdlet.
Here's an example of using the pipeline to get the services that are running on the local machine and are set to start automatically:
Get-Service | Where-Object { $_.Status -eq "Running" } | Where-Object { $_.StartType -eq "Automatic" } You can also use the Foreach-Object cmdlet to process the output of a cmdlet one object at a time:
Get-Service | Where-Object { $_.Status -eq "Running" } | Foreach-Object { Write-Output "$($_.Name) is running." } You can find more information about the PowerShell pipeline in the PowerShell documentation or by using the Get-Help cmdlet. For example:
Get-Help about_Pipelines
In PowerShell, you can use the .NET Framework to create and manipulate .NET objects. To do this, you can use the New-Object cmdlet to create an instance of a .NET class, and then use dot notation to access the properties and methods of that object.
For example, to create a System.DateTime object representing the current date and time, you can use the following command:
$date = New-Object System.DateTime
To access the properties of the object, you can use dot notation. For example, to access the year, month, and day of the current date, you can use the following commands:
$year = $date.Year $month = $date.Month $day = $date.Day
You can also use dot notation to call methods of the object. For example, to add two days to the current date, you can use the following command:
$newDate = $date.AddDays(2)
In addition to creating new objects, you can also work with existing .NET objects that are returned by cmdlets or functions. For example, the Get-Process cmdlet returns a System.Diagnostics.Process object for each process on the system. You can use dot notation to access the properties and methods of these objects in the same way as with any other .NET object.
For more information on working with .NET objects in PowerShell, you can review the Microsoft documentation on the topic.
This type of questions is asked in PowerShell interview questions for advanced level or a level below advanced.
To create an advanced function in PowerShell, you can use the Function keyword followed by the name of the function and any parameters it should accept. For example:
Function MyFunction
{
# function body goes here
} To add parameter validation to a function, you can use the Param block at the beginning of the function. For example:
Function MyFunction
{
Param
(
[Parameter(Mandatory=$true)]
[string]$Name,
[Parameter(Mandatory=$true)]
[int]$Age
)
# function body goes here
} This defines two parameters for the function, Name and Age, both of which are required (mandatory). You can also specify other options for the parameters, such as their data type and whether they are mandatory or optional.
To add help documentation to a function, you can use the Comment-Based Help syntax. This consists of a series of specially formatted comments at the beginning of the function that contain the help documentation. For example:
Function MyFunction
{
<#
.SYNOPSIS
This is a brief summary of the function.
.DESCRIPTION
This is a more detailed description of the function.
.PARAMETER Name
This is a description of the Name parameter.
.PARAMETER Age
This is a description of the Age parameter.
.EXAMPLE
MyFunction -Name "John" -Age 30
#>
Param
(
[Parameter(Mandatory=$true)]
[string]$Name,
[Parameter(Mandatory=$true)]
[int]$Age
)
# function body goes here
} You can then use the Get-Help cmdlet to display the help documentation for the function. For example:
Get-Help MyFunction
This will display the summary, description, and parameter information for the function.
This type of questions are PowerShell interview questions advanced level.
One of the most frequently posed PowerShell scenario based interview questions, be ready for this conceptual question.
To create a PowerShell module, you can create a folder with the same name as the module and then create one or more PowerShell scripts or functions within that folder. For example, if you wanted to create a module called MyModule, you could create a folder called MyModule and then add your scripts or functions to that folder.
To expose the functions and scripts in your module to the PowerShell environment, you can create a module manifest file, which is a PowerShell script with a .psd1 extension that defines the module's metadata and specifies which functions and scripts should be imported into the PowerShell environment when the module is loaded.
For example, suppose you have a function called MyFunction in a script called MyScript.ps1 within your MyModule folder. To create a module manifest for this module, you could create a file called MyModule.psd1 with the following content:
@{
ModuleVersion = '1.0'
Author = 'John Smith'
Description = 'This is my PowerShell module.'
FunctionsToExport = '*'
CmdletsToExport = '*'
VariablesToExport = '*'
AliasesToExport = '*'
PrivateData = @{
PSData = @{
Functions = @('MyFunction')
Scripts = @('MyScript.ps1')
}
}
} This manifest file specifies the metadata for the module, such as its version and author, as well as the functions, cmdlets, variables, and aliases that should be exported when the module is imported. It also specifies the scripts and functions that are included in the module.
To publish your module, you can use the Publish-Module cmdlet. For example:
Publish-Module -Name MyModule -NuGetApiKey xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx -Repository PSGallery
This will publish your module to the PowerShell Gallery, which is a central repository for PowerShell modules. You will need to provide a NuGet API key to authenticate the publishing process.
Once your module is published, other users will be able to install and use it by running the Install-Module cmdlet and specifying the name of your module. For example:
Install-Module -Name MyModule
This will install your module and make its functions and scripts available to the PowerShell environment.
PowerShell allows you to work with .NET assemblies and COM objects in several ways.
To work with .NET assemblies, you can use the Add-Type cmdlet to load the assembly and access its types and members. For example:
Add-Type -AssemblyName System.Web
# create an instance of the HttpUtility class
$httpUtility = New-Object System.Web.HttpUtility
# use the HtmlEncode method to encode a string
$encodedString = $httpUtility.HtmlEncode("<html>") You can also use the [Reflection.Assembly]::Load() method to load an assembly and the [Type]::GetType() method to get a type from the assembly. For example:
[Reflection.Assembly]::Load("System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")
# get the HttpUtility type
$httpUtilityType = [Type]::GetType("System.Web.HttpUtility, System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")
# create an instance of the HttpUtility class
$httpUtility = New-Object $httpUtilityType
# use the HtmlEncode method to encode a string
$encodedString = $httpUtility.HtmlEncode("<html>") To work with COM objects, you can use the New-Object cmdlet with the -ComObject parameter to create an instance of the COM object. You can then use the methods and properties of the COM object like you would any other .NET object.
For example, to work with the Excel COM object, you could use the following code:
# create an instance of the Excel COM object $excel = New-Object -ComObject Excel.Application # make Excel visible $excel.Visible = $true # create a new workbook
To work with the Windows API in PowerShell, you can use the Add-Type cmdlet to define a new .NET type that wraps the API function you want to call. You can then call the API function using the .NET type you created.
For example, suppose you want to call the MessageBox function from the user32.dll library. You could use the following code:
# define the MessageBox function as a .NET method
Add-Type -Name MessageBox -MemberDefinition @"
[DllImport("user32.dll")]
public static extern int MessageBox(IntPtr hWnd, string text, string caption, uint type);
"@ -Namespace Win32
# call the MessageBox function
[Win32.MessageBox]::MessageBox([IntPtr]::Zero, "Hello, World!", "Hello", 0) This will create a .NET method called MessageBox that wraps the MessageBox function from user32.dll, and then call the function to display a message box.
You can use this same technique to call any function from a Windows DLL. You just need to know the function's name, the DLL it is located in, and its parameters and return type. You can find this information in the documentation for the Windows API or by using tools such as Dependency Walker or Windows API Viewer. These tools can help you find the names and locations of DLLs and functions, as well as the parameters and return types for the functions.
It is also possible to use the .NET Framework's System.Runtime.InteropServices namespace to access the Windows API. This namespace provides classes and methods for calling DLL functions and working with COM objects, and can make it easier to work with the Windows API in .NET languages such as C# and PowerShell.
For example, to call the MessageBox function using the System.Runtime.InteropServices namespace, you could use the following code:
# import the System.Runtime.InteropServices namespace
Add-Type -AssemblyName System.Runtime.InteropServices
# call the MessageBox function using the InteropServices namespace
[System.Runtime.InteropServices.Marshal]::CallWindowProc(
[System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer([System.Runtime.InteropServices.Marshal]::GetProcAddress(
[System.Runtime.InteropServices.Marshal]::LoadLibrary("user32.dll"), "MessageBoxA"), 'IntPtrIntPtrStrStrUInt', 'Int32'),
[IntPtr]::Zero, "Hello, World!", "Hello", 0) This code uses the Marshal class from the System.Runtime.InteropServices namespace to load the user32.dll library, get the address of the MessageBoxA function, and call the function using a delegate.
One of the most frequently posed PowerShell scenario based interview questions, be ready for this conceptual question.
PowerShell allows you to create custom formatting and type extension commands to customize the way objects are displayed and to add custom behavior to .NET types.
To create a custom formatting command, you can create a formatting file that defines the formatting rules for your objects. A formatting file is a PowerShell script with a .ps1xml extension that contains a series of View elements, each of which defines a set of formatting rules for a particular type of object.
For example, suppose you have a custom object type called Person with properties such as Name and Age. You could create a formatting file called Person.format.ps1xml with the following content:
<?xml version="1.0" encoding="utf-8"?> <Configuration> <ViewDefinitions> <View> <Name>Person</Name> <ViewSelectedBy> <TypeName>Person</TypeName> </ViewSelectedBy> <TableControl> <TableHeaders> <TableColumnHeader> <Label>Name</Label> </TableColumnHeader> <TableColumnHeader> <Label>Age</Label> </TableColumnHeader> </TableHeaders> <TableRowEntries> <TableRowEntry> <TableColumnItems> <TableColumnItem> <PropertyName>Name</PropertyName> </TableColumnItem> <TableColumnItem> <PropertyName>Age</PropertyName> </TableColumnItem> </TableColumnItems> </TableRowEntry> </TableRowEntries> </TableControl> </View> </ViewDefinitions>
For example, suppose you have a custom object type called Person with properties Name and Age. You can create a custom formatting command to display the object in a specific way by using the following code:
# define the custom formatting command
function Format-Person
{
[CmdletBinding()]
param(
[Parameter(ValueFromPipeline)]
[Person]$InputObject
)
process
{
# return a string that displays the person's name and age
return "$($InputObject.Name) ($($InputObject.Age))"
}
}
# register the custom formatting command for the Person object type
$pscmdlet.psstandardmembers.DefaultDisplayPropertySet.Clear()
$pscmdlet.psstandardmembers.DefaultDisplayPropertySet.Add((New-Object System.Management.Automation.PSPropertySet('DefaultDisplayPropertySet', [String[]]@('Name', 'Age'))))
# create a custom formatter for the Person object type
$personFormatter = {
if ($_ -is [Person])
{
# use the custom formatting command to format the object
return Format-Person $_
}
else
{
# use the default formatting for other object types
return $_ | Format-List
}
} To register the custom formatter, you can use the Update-FormatData cmdlet. For example:
Update-FormatData -PrependFormatter $personFormatter
This will add the custom formatter to the beginning of the list of formatters, so it will be used before the default formatters.
Now, when you output a Person object to the console or convert it to a string, it will be formatted using the custom formatter. For example:
# create a Person object
$person = [Person]::new("John", 30)
# output the Person object to the console
$person
# convert the Person object to a string
$person.ToString() This will display the person's name and age using the custom formatting command.
To create a type extension command, you can use the Update-TypeData cmdlet to add methods, properties, and other members to an existing .NET type. For example:
# add a method to the System.String type
Update-TypeData -TypeName System.String -MemberType ScriptMethod -MemberName Reverse -Value { $this | ForEach-Object {$_} | Sort-Object -Descending }
# add a property to the System.String type
Update-TypeData -TypeName System.String -Member 
