WhatIf and Confirm support in PowerShell - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the -WhatIf parameter do in PowerShell?

It shows what would happen if a command runs, without actually making any changes. It's like a preview or a dry run.

beginner

What is the purpose of the -Confirm parameter in PowerShell?

It asks you to confirm before running a command that changes something. You get a yes/no question to avoid mistakes.

intermediate

How do you add -WhatIf support to your own PowerShell function?

Add [CmdletBinding(SupportsShouldProcess=$true)] at the top and use $PSCmdlet.ShouldProcess() inside your function to check if it should run.

beginner

What happens if you run a command with -Confirm and answer 'No'?

The command stops and does not make any changes. This helps prevent unwanted actions.

beginner

Why is it good practice to support -WhatIf and -Confirm in scripts?

It helps users avoid mistakes by previewing changes and asking for confirmation, making scripts safer to run.

What does the -WhatIf parameter do when added to a PowerShell command?

A Shows what would happen without making changes

B Automatically confirms the command

C Runs the command silently

D Cancels the command immediately

-WhatIf previews the command's effect without changing anything.

Which attribute enables -WhatIf support in a PowerShell function?

A [CmdletBinding(SupportsShouldProcess=$true)]

B [Parameter(Mandatory=$true)]

C [OutputType([string])]

D [ValidateSet()]

This attribute tells PowerShell the function supports -WhatIf and -Confirm.

What does the $PSCmdlet.ShouldProcess() method do inside a function?

A Stops the script immediately

B Prints the command output

C Checks if the command should run based on <code>-WhatIf</code> or <code>-Confirm</code>

D Runs the command without confirmation

It checks if the user wants to proceed, respecting -WhatIf and -Confirm.

If you run a command with -Confirm and choose 'No', what happens?

A The command runs anyway

B The command runs silently

C The command runs twice

D The command does not run

Answering 'No' cancels the command to prevent changes.

Why should script authors add -WhatIf and -Confirm support?

A To hide script output

B To make scripts safer and prevent accidental changes

C To make scripts run faster

D To disable user interaction

These features help users avoid mistakes by previewing and confirming actions.

Explain how to add WhatIf and Confirm support to a PowerShell function.

Think about the attribute and method that enable this support.

Describe the difference between -WhatIf and -Confirm parameters in PowerShell.

One previews, the other asks permission.