WhatIf and Confirm support in PowerShell - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output when using -WhatIf with Remove-Item?

Consider the following PowerShell command:

Remove-Item -Path 'C:\Temp\file.txt' -WhatIf

What will this command output?

PowerShell

Remove-Item -Path 'C:\Temp\file.txt' -WhatIf

A Prompt asking 'Are you sure you want to delete C:\Temp\file.txt?'

B What if: Performing the operation "Remove File" on target "C:\Temp\file.txt".

C Error: Remove-Item does not support -WhatIf parameter.

D File 'C:\Temp\file.txt' is deleted silently with no output.

💡 Hint

The -WhatIf parameter shows what would happen without making changes.

The -WhatIf parameter simulates the command and outputs a message describing the action without performing it.

💻 Command Output

intermediate

What happens when Confirm is set to true on Stop-Process?

Given the command:

Stop-Process -Name notepad -Confirm:$true

What will PowerShell do when this runs?

PowerShell

Stop-Process -Name notepad -Confirm:$true

A It throws an error because -Confirm does not accept boolean values.

B It stops all notepad processes immediately without asking.

C It prompts the user to confirm stopping each notepad process.

D It silently ignores the command without stopping any process.

💡 Hint

The -Confirm parameter controls user confirmation prompts.

Setting -Confirm:$true forces PowerShell to ask for confirmation before stopping each process.

📝 Syntax

advanced

Identify the correct way to add WhatIf support in a custom function

You want to add WhatIf support to this PowerShell function:

function Remove-MyFile {
  param([string]$Path)
  Remove-Item -Path $Path
}

Which option correctly adds WhatIf support?

PowerShell

function Remove-MyFile {
  param([string]$Path)
  Remove-Item -Path $Path
}

A Add [CmdletBinding(SupportsShouldProcess=$true)] above function and use if ($PSCmdlet.ShouldProcess($Path)) { Remove-Item -Path $Path }

B Add param([switch]$WhatIf) and inside function use if ($WhatIf) { Write-Output "WhatIf: $Path" } else { Remove-Item -Path $Path }

C Add -WhatIf parameter to Remove-Item call directly without changes to function declaration

D Add SupportsWhatIf=$true in param block and call Remove-Item normally

💡 Hint

WhatIf support requires CmdletBinding and ShouldProcess method.

To support -WhatIf, the function must declare CmdletBinding with SupportsShouldProcess and call ShouldProcess before action.

🔧 Debug

advanced

Why does this function not prompt for confirmation despite -Confirm:$true?

Given this function:

function Remove-MyFile {
  param([string]$Path)
  Remove-Item -Path $Path -Confirm:$true
}

When calling Remove-MyFile -Path 'C:\temp\file.txt' -Confirm:$true, no confirmation prompt appears. Why?

PowerShell

function Remove-MyFile {
  param([string]$Path)
  Remove-Item -Path $Path -Confirm:$true
}

A PowerShell disables confirmation prompts by default.

B Remove-Item does not support -Confirm parameter.

C The -Confirm parameter must be passed to the function, not inside Remove-Item.

D The function does not declare CmdletBinding with SupportsShouldProcess, so -Confirm is ignored.

💡 Hint

Confirm support requires CmdletBinding with SupportsShouldProcess in functions.

Without CmdletBinding(SupportsShouldProcess=$true), the function does not support -Confirm and the parameter is ignored.

🚀 Application

expert

How to implement both WhatIf and Confirm support in a custom PowerShell function?

You want to create a PowerShell function that deletes a file and supports both -WhatIf and -Confirm parameters natively. Which code snippet correctly implements this?

A

[CmdletBinding(SupportsShouldProcess=$true, ConfirmImpact='Medium')]
param([string]$Path)
if ($PSCmdlet.ShouldProcess($Path)) {
  Remove-Item -Path $Path
}

B

param([string]$Path, [switch]$WhatIf, [switch]$Confirm)
if ($WhatIf) { Write-Output "WhatIf: Remove $Path" } elseif ($Confirm) { Read-Host 'Confirm deletion?'; Remove-Item -Path $Path } else { Remove-Item -Path $Path }

C

[CmdletBinding()]
param([string]$Path)
Remove-Item -Path $Path -WhatIf:$WhatIf -Confirm:$Confirm

D

param([string]$Path)
Remove-Item -Path $Path -WhatIf -Confirm

💡 Hint

Use CmdletBinding with SupportsShouldProcess and call ShouldProcess method.

To support -WhatIf and -Confirm, the function must declare CmdletBinding with SupportsShouldProcess and call ShouldProcess before performing the action.