Powershell: Colon in commandlet parameters

by

When you do:

Move-ActiveMailboxDatabase -Confirm $false

you are not saying Confirm parameter accepts the $false. You are saying -Confirm and also passing an (separate) argument to the cmdlet with value $false.

Since Confirm is a switch, just the presence of -Confirm means it is true. Absence of -Confirm means it is false.

Let me give you a script example:

param([switch]$test)

write-host Test is $test

If you just run the script without any arguments / paramters i.e .\script.ps1 you get output:

Test is False

If you run it as .\script.ps1 -test, the output is

Test is True

If you run it as .\script.ps1 -test $false, the output is

Test is True

If you run it as .\script.ps1 -test:$false the output is

Test is False

It is in scenarios where the value for a switch variable itself has to be determined from another variable that the : is used.

For example, consider the script:

param ([boolean]$in)

function func([switch] $test){
write-host Test is $test
}

func -test:$in

Here if you run it as .\script.ps1 -in $false, you get

Test is false

If you weren’t able to use the :, you would have had to write it as:

if($in){  func -test}
else { func }

More Related Contents:

  1. Powershell function call changing passed string into int
  2. PowerShell’s parsing modes: argument (command) mode vs. expression mode
  3. How do I capture the output into a variable from an external process in PowerShell?
  4. Running a powershell command using full path and arguments from command line [duplicate]
  5. Character-encoding problem with string literal in source code
  6. How to handle failed variable assignments in powershell? [duplicate]
  7. Delete files older than 15 days using PowerShell
  8. Output (“echo”) a variable to a text file
  9. Powershell equivalent of bash ampersand (&) for forking/running background processes
  10. INI file parsing in PowerShell
  11. Parameter interpretation when running jobs
  12. Powershell: Uninstall application by UpgradeCode
  13. Export-CSV exports length but not name
  14. How to properly -filter multiple strings in a PowerShell copy script
  15. Write-Host vs Write-Information in PowerShell 5
  16. Methods to hex edit binary files via Powershell
  17. How remove accents in PowerShell?
  18. Unable to convert a string to an integer variable from DateTaken attribute on a JPG file
  19. How to Grant permission to user on Certificate private key using powershell?
  20. Using Invoke-Command -ScriptBlock on a function with arguments
  21. Why does “Get-ChildItem -File | Get-FileHash” work?
  22. Powershell Using Start-Process in PSSession to Open Notepad
  23. Powershell – Reboot and Continue Script
  24. Hashtables and key order
  25. Executing powershell command directly in jenkins pipeline
  26. Temporarily change powershell language to English?
  27. Is there a powershell pattern for if($?) { }
  28. How to uninstall an app that another user installed?
  29. Uploading file to HTTP via Powershell
  30. Strange behavior for PowerShell Length after ForEach method

Leave a Comment