PowerShell, call script with parameter without a value, like a script with options

Question

Is it possible to call a PowerShell script with options? Like a parameter without a value.

For instance I currently use:

param (     $lastmonth=0 ); 

in the script. Now I can use the call

script.ps1 -lastmonth 1 

or

script.ps1  

and use $lastmonth for controlling the flow.

But I'd like to have the calls like

script.ps1 -lastmonth 

and

script.ps1 

and control the flow depending on whether -lastmonth was given, or not.

Answer 1

Set the type of your parameter to [switch], e.g.

param (     [switch]$lastmonth ); 

EDIT: Note that the variable will be a boolean. You can test it like:

if ($lastMonth) {     Write-Host "lastMonth is set." } else {     Write-Host "lastMonth is not set." } 

(thanks Chris)