Powershell advanced functions: are optional parameters supposed to get initialized?

Posted by Richard Berg on Stack Overflow See other posts from Stack Overflow or by Richard Berg
Published on 2010-01-22T16:42:10Z Indexed on 2010/04/27 3:33 UTC
Read the original article Hit count: 440

Filed under:

powershell

|

function

|

parameters

|

powershell-v2.0

filter CountFilter($StartAt = 0) 
{ 
    Write-Output ($StartAt++) 
}

function CountFunction
{
    [CmdletBinding()]
    param (
        [Parameter(ValueFromPipeline=$true, Mandatory=$true)]
        $InputObject,
        [Parameter(Position=0)]
        $StartAt = 0
    )

    process 
    { 
        Write-Output ($StartAt++) 
    }
}

$fiveThings = $dir | select -first 5  # or whatever

"Ok"
$fiveThings | CountFilter 0

"Ok"
$fiveThings | CountFilter

"Ok"
$fiveThings | CountFunction 0

"BUGBUG ??"
$fiveThings | CountFunction

I searched Connect and didn't find any known bugs that would cause this discrepancy. Anyone know if it's by design?

© Stack Overflow or respective owner

Related posts about powershell

In Powershell on Windows7, how do I automatically set aliases (or run scripts) when powershell loads

as seen on Super User - Search for 'Super User'
I have created a powershell cmdlet and assigned it to an Alias. How do I do this automatically every time powershell launches? (i.e. so I don't have to re-assign the alias every time) >>> More
How to Load commands into your powershell profile to run on starting powershell

as seen on Server Fault - Search for 'Server Fault'
Hi, I have found a way to load exchange 2010 powershell into powershell running on a windows xp workstation, however there are a few commands that need to run. I was wondering how I could load them into a profile somehow. These are the commands that I need to run before I can do any of the exchange… >>> More
C#, Powershell - Microsoft.Exchange.Management.PowerShell.Admin

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm having troubles using the Microsoft.Exchange.Management.PowerShell.Admin on a server. The server is not the one running Exchange 2007, it's a remote server (in the same zone). I can't figure out how to add the Snapin for Powershell - Microsoft.Exchange.Management.PowerShell.Admin. Is it possible… >>> More
PowerShell Script to Create PowerShell Profile

as seen on Geeks with Blogs - Search for 'Geeks with Blogs'
Utilizing a PowerShell profile can help any PowerShell user save time getting up and running with their work. For those unfamiliar a PowerShell profile is a file you can store any PowerShell commands that you want to run when you fire up a PowerShell console (or ISE.) In my typical profiles (example… >>> More
Download Free PowerShell Quick Reference Guides from Microsoft

as seen on How to geek - Search for 'How to geek'
Are you just getting started with learning PowerShell or tired of looking up less frequently used commands? Then this terrific set of PowerShell quick reference guides from Microsoft is just what you need! The first guide focuses on commonly-used Windows PowerShell commands and is available in a single… >>> More

Related posts about function

MAMP + Python MySQLDB - trouble installing

as seen on Server Fault - Search for 'Server Fault'
I'm currently running the latest version of MAMP on my Snow Leopard OSX, and I'm trying to install MySQLDB. Downloaded: MySQL-python-1.2.3c1 I went into the setup_posix.py and adjusted the location of the mysql_config to the one in MAMP: mysql_config.path = "/Applications/MAMP/Library/bin/mysql_config" When… >>> More
Compiling a program with a legacy version of gcc

as seen on Stack Overflow - Search for 'Stack Overflow'
This is probably a very difficult problem to troubleshoot with the information I can practically provide, but I'm hoping someone might be able to at least point me in a possible direction. I'm trying to install HTK (http://htk.eng.cam.ac.uk/), which, according to this page needs to be installed using… >>> More
eventmachine on debian fails install via rubygems

as seen on Stack Overflow - Search for 'Stack Overflow'
this has been killing me for the last 5 hours. I don't seem to be able to get eventmachine running on my debian box. here this output: $ gem install thin Building native extensions. This could take a while... ERROR: Error installing thin: ERROR: Failed to build gem native extension. … >>> More
Can overloading is possible with two version of function, constant member function and function with

as seen on Stack Overflow - Search for 'Stack Overflow'
Hello, I just came across various overloading methods like type of parameter passed, varying number of parameters, return type etc. I just want to know that can I overload a function with following two version //function which can modify member String& MyClass::doSomething(); //constant member… >>> More
[PHP] function().function() VS function()function()

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi all, I was writing a foreach Loop in PHP5. Here is the script: foreach(range('A','Z') as $char) // line 1 { // line 2 echo strtoupper($char)strtolower($char); // line 3 } // line 4 And I got this error message Parse error: parse error, unexpected T_STRING in testing.php on line 3 I spent almost… >>> More