Question

PowerShell - Array of arrays

Asked by: PC_User321

I have data in a pipeline from which I want to create an array of arrays like, for example:
  (a, XXa), (b, XXb), (c, XXc)
I don't want to use a pre-declared multi-dimensional array because it is messy and I don't know in advance how big it will need to be.

This code does not work - is gives a length of 6
$arrayOfArrays = ("a","b","c") | %{($_, "XX$_")}
# Check if it worked:
"arrayOfArrays[2] = " + $arrayOfArrays[2]
"Length = " + $arrayOfArrays.length


This code works but it is messy:
$tmp = @(1)
$arrayOfArrays = @()

("a","b","c") | %{ $tmp[0] = ($_, "XX$_"); $arrayOfArrays += $tmp;}
# Check if it worked:
"arrayOfArrays[2] = " + $arrayOfArrays[2]
"Length = " + $arrayOfArrays.length

Is there a better way?

This Question has been solved and asker verified All Experts Exchange premium technology solutions are available to subscription members.

Subscribe now for full access to Experts Exchange and get

Instant Access to this Solution

  • Plus...
  • 30 Day FREE access, no risk, no obligation
  • Collaborate with the world's top tech experts
  • Unlimited access to our exclusive solution database
  • Never be left without tech help again

Subscribe Now

Asked On
2008-01-28 at 14:52:01ID23117816
Tags

PowerShell

Topic

Powershell

Participating Experts
1
Points
200
Comments
6

Trusted by hundreds of thousands everyday for fast, accurate and reliable tech support.

  • "The time we save is the biggest benefit of Experts Exchange to Warner Bros. What could take multiple guys 2 hours or more each to find is accessed in around 15 minutes on Experts Exchange." Mike Kapnisakis, Warner Bros.
  • "Our team likes having a resource that is more secure than just using Google and most experts using this service really know their stuff. It's nice to look here first versus using Google." Dayna Sellner, Lockheed Martin
  • "Anytime that I've been stumped with a problem, 9 out of 10 times Experts Exchange has either the accepted solution or an open discussion of the potential solution to the problem." Kenny Red, eBay Inc.

See what Experts Exchange can do for you.

Got a question?

We've got the answer.

Experts Exchange has been collecting answers to technology questions since 1996…3 million and counting! If you have a question, chances are we already have your answer.

Screenshot of Experts Exchange Knowledgebase

Need individual assistance?

Our experts are ready to help.

If you can't find the exact answer you're looking for, ask our exclusive community of 50,000 experts. You’ll get a personalized answer from a trusted professional.

Screenshot of Experts Exchange Knowledgebase

Want to learn from the best?

Read articles from industry experts.

Thousands of free tech tips, tricks, how-to’s and tutorials are available in our peer reviewed articles section. See for yourself how smart our experts are, no login required.

Screenshot of an Article

Working on a long term project?

Store your work and research.

Save solutions to your questions, answers you’ve discovered through searching plus helpful articles in your personal knowledgebase for easy future access.

Screenshot of Experts Exchange Knowledgebase

Access the answers to your technology questions today.

Subscribe Now

30-day free trial. Register in 60 seconds.

What Makes Experts Exchange Unique?

Members of the expert community talk about why the experience at Experts Exchange is different than what you will find anywhere else.

Trusted by the world's most respected brands.

image of each brand's logo

Faithfully serving IT professionals since 1996.

Experts Exchange Logo

Try it out and discover for yourself.

Subscribe Now

30-day free trial. Register in 60 seconds.

Related Solutions

  1. messy
    I have a very messy question. I'll try to have it make sense, but I'm not sure I can. I'm used to putting all information used in a program straight into the code. However, I'm making a program that I want the user to be able to update on his own. I'm doing this by putting ...
  2. Dimension of Array
    Q:How to determine how many dimension an array is? Here where I will use: I have function like this: 'determine size of matrix A Public Function MSize(matrix) Dim maxRow As Integer, maxCol As Integer maxRow = UBound(matrix, 1) - LBound(matrix, 1) + 1 On Error GoTo HandleErro...
  3. multi-dimension array
    I have a string array String[] name = {"Bob","Zack"}; and a int array int[] age={"11","11"}; How would insert these two values into an multi-dimension array ?
  4. Controling pipeline execution in windows powershell
    HI I have a set of PS commands C1, C2 to Cn Those commands are sent from the front end to the back end which executes the commands and return the results. Up to now, all commands were synchronous, so, executing C1 | C2 is OK. Now, part of the commands are going to be asynch...

Free Tech Articles

  1. WARNING: 5 Reasons why you should NEVER fix a computer for free.
    It is in our nature to love the puzzle. We are obsessed. The lot of us. We love puzzles. We love the challenge. We thrive on finding the answer. We hate disarray. It bothers us deep in our soul. W...
  2. SCCM OSD Basic troubleshooting
    SCCM 2007 OSD is a fantastic way to deploy operating systems, however, like most things SCCM issues can sometimes be difficult to resolve due to the sheer volume of logs to sift through and the dispe...
  3. Migrate Small Business Server 2003 to Exchange 2010 and Windows 2008 R2
    This guide is intended to provide step by step instructions on how to migrate from Small Business Server 2003 to Windows 2008 R2 with Exchange 2010. For this migration to work you will need the fo...
  4. Create a Win7 Gadget
    This article shows you how to create a simple "Gadget" -- a sort of mini-application supported by Windows 7 and Vista. Gadgets can be dropped anywhere on the desktop to provide instant information, ...
  5. Outlook continually prompting for username and password
    There have been a lot of questions recently regarding Outlook prompting for a username and password whilst using Exchange 2007. There are a few reasons why this would happen and I will try to cover t...
  6. Backup Exchange 2010 Information Store using Windows Backup
    There seems to be quite a lot of confusion around the ability to backup Exchange 2010 using the built in Windows Backup feature. This stems from the omission of this feature prior to Exchange 2007 s...

Cloud Class Webinars

  1. Avoiding Bugs in Microsoft Access
    Alison Balter takes and in-depth look at avoiding bugs in Access. In this webinar you will learn about using the immediate window to debug your applications, invoking the debugger, using breakpoints to troubleshoot, stepping through code, setting the next statement to execute, ...
  2. Top 10 Best New Features in Visio 2010
    Scott Helmers gives live demonstrations of the top 10 new features in Visio 2010. This webinar will teach you how to create compelling diagrams by adding shapes to the page with a single click, linking the shapes in a diagram to data in Excel (or SQL Server, or SharePoint), ...
  3. IT Consultant Business Secrets Revealed
    Michael Munger, Experts Exchange tech pro and IT consultant, pulls back the curtain on his very successful businesses and answers question on every IT consultant and business owner should know about. He shares secrets on what he did to solve the 5 most common problems in IT, ...
  4. Disaster Recovery and Business Continuity
    Quest CTO, Mike Billon, gives an overview of the steps involved in building a dunamic disaster recovery plan. Through case studies and an examination of software/hardware tooles for monitoring and testing, you'll gain a better understandin of where you are, where you want ...
  5. Organize Your Visio Diagrams with Containers and Lists
    Scott Helmers uses cross functional flowcharts, wireframe diagrams, data graphic legends and seating charts to teach you: how to ustilize all three new structured diagram components in Visio 2010, the best practices for organizeing shapes in previous version of Visio, how to organize ...
  6. How to Us Objects, Properties, Events and Methods in Microsoft Access
    Alison Dalter gives an in-depbth look at objects, properties, events and methods in Microsoft Access. In this webinar you will learn about using the object browser, referring to objects, working with properties and methods, working with object variables, understanding the ...

Join the Community

Give a Little. Get a Lot.

Join the community of experts here and help other tech pros by answering question in your area of expertise. You can earn FREE access to all Experts Exchange's premium features and resources.

Join the Community

Answers

 

by: BSonPoshPosted on 2008-01-28 at 16:26:42ID: 20764336

Why do you think you will need a multi-dimensional array

Simply put in Powershell it just doesn't seem needed. You can already nest arrays.

$MyBaseArray = @()
1..10 | %{$internalArray = 11..20;$MyBaseArray += $internalArray}
$MyBaseArray

Perhaps if I better understand what your attempting I can help.

 

by: BSonPoshPosted on 2008-01-29 at 07:28:28ID: 20768553

I been looking at this I think a hash table is perfect (if understand where your going)

Let me know if this is what your looking for

$data = @{}
("a","b","c") | foreach{$data.$_ = "xx$_"}
$data

Output:
Name                       Value                                                                                  
----                           -----                                                                                  
a                              xxa                                                                                    
b                              xxb                                                                                    
c                              xxc  

 

by: PC_User321Posted on 2008-01-30 at 00:41:21ID: 20775514

Thanks for your comment, BSonPosh.
My question is not about how to get a particular task accomplished, but rather a complain about what looks like a limitation of the language.

In my example I have an array to which I want to add (a, XXa), but I need a way of indicating to PowerShell that those 2 elements should be added as ONE ARRAY, and not as two separate thing.
And this way of indicating to PowerShell should work in a pipeline situation as I have shown in my example.

On page 71 of "PowerShell In Action", Bruce Payette says:
"Here is how array literals are defined in PowerShell: They're not. There is no array literal notation in PowerShell. .... If you need an array, one will be created for you."

Well, Bruce, in my first example I needed an array and one was NOT created for me.
I feel that PowerShell SHOULD have an array literal, like Perl has.
Or perhaps there is an elegant way of achieving this that I haven't figured out.

The essence of my question is, in my context (with a pipeline) how do I tell PowerShell that I want to add one array, not two array elements.

Thanks.

 

by: BSonPoshPosted on 2008-01-30 at 05:16:15ID: 20776687

I will pass this on to Bruce and the team and get a"Devish" answer.

You can create a literal Array by doing this
$tmp = @()

I think the problem is that Powershell sees two arrays and instead of adding one array to the other it seems to join them.

I do this all the time with custom objects, but I haven't tried specifically with two arrays.

 

by: BSonPoshPosted on 2008-01-30 at 09:21:59ID: 20778919

Two fellow MVPs provided this explaination (Kirk and Karl)

######################################
The pipeline (and certian other operations) will try to Strip an array(or any collection/Ienumerable), so that it can push it down the pipeline one item at a time.. the , just wraps something into an array.. so often if you already have an array you use the , to put that array inside an array , so that when the pipeline strips it, it just pushes the original array down the pipeline as ONE item. look at this
,,,(
1..5)
You will notice the 5 element array is inside a one element array which is inside a one element array which is inside a one element array..
 
now run each of these
,,,(
1..5) | % { $_ }
,,,(1..5) | % { $_ } | % { $_ }
,,,(1..5) | % { $_ } | % { $_ } | % { $_ }
 
you'll see that the "container arrays" get strip at each pipeline level, with the Last line, having been run through a pipeline boundary 3 times, you get the final container array stripped, and the pipeline gets the the items stripped and pushed down one at a time..

 

by: PC_User321Posted on 2008-01-30 at 23:30:42ID: 20784645

Excellent answer.  Points increased.

I added a comma in front of the brackets that enclose the array I want to add, and the array now gets added as a single entitiy, just as K & K explained.

Thanks.

20120131-EE-VQP-002

3 Ways to Join

30-Day Free Trial

The Experts

98% positive feedback on 31,087 answers since March 2000. angeliii is a Microsoft Most Valuable Professional for his work with MS SQL Server & Develoment.

He has also proven his knowledge of Visual Basic Programming, PHP Scripting and Oracle Databases.

The Experts

97% positive feedback on 10,752 answers since July 2000. lrmoore has more than 18 years experience in the networking industry.

The six-time Mircosoft MVPs specialties include firewalls, virtual private networking, and network management.

Testimonials

"...and excellent source for support... Kind of like having your very own IT dept." Electriciansnet

Testimonials

"I was apprehensive at signing up at first. However... it has already made my life as an IT administrator much easier." JaCrews

Testimonials

"WOW! You guys have great, active, and knowledgeable people on here." moore50

Business Clients

Business Clients

In the Press

"If you’ve got a question... Experts Exchange can supply an answer.”

In the Press

"...an invaluable aid for both IT professionals and those who require tech support."

In the Press

"where IT professionals provide quick answers on just about any topic"

Business Account Plans

Loading Advertisement...