# Completely dumb iterator question from a newbie

**URL:** <https://www.ruby-forum.com/t/completely-dumb-iterator-question-from-a-newbie/122485>\
**Category:** Ruby\
**Created:** [December 8, 2007, 2:04am UTC](https://www.ruby-forum.com/t/completely-dumb-iterator-question-from-a-newbie/122485 "2007-12-08T02:04:50Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![StecklyS\_Ron](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/dfb087/32.png) [@StecklyS\_Ron](https://www.ruby-forum.com/u/StecklyS_Ron)\
**Post date:** [December 8, 2007, 2:04am UTC](https://www.ruby-forum.com/t/completely-dumb-iterator-question-from-a-newbie/122485/1 "2007-12-08T02:04:50Z")

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Hi all,

So I have a question about iteration. Here’s some code I saw on Ruby on  
Windows:

inbox.Items.each do |message|  
message.Attachments.each do |attachment|  
filename = “c:\attachments\#{attachment.FileName}”  
attachment.SaveAsFile(filename)  
File.delete(filename) if File.size(filename) \< 500000  
end  
end

What I find troubling is ‘message,’. How do we know the variable to  
iterate over? I have the same issue with VBScript, where the same code  
would be:

For each objMessage in colItems

```
            Etc.

```

Next

The thing that’s bothering me is where people decide the thing to  
iterate over. How do you decide what to put between the pipes | |?

Sorry for the retarded question,

Ron

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**Author:** ![StecklyS\_Ron](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/dfb087/32.png) [@StecklyS\_Ron](https://www.ruby-forum.com/u/StecklyS_Ron)\
**Post date:** [December 8, 2007, 2:12am UTC](https://www.ruby-forum.com/t/completely-dumb-iterator-question-from-a-newbie/122485/2 "2007-12-08T02:12:53Z")

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Ron,

Don’t worry, no question is ‘retarded’ or dumb. You can decide to put  
any sane string between the pipes. However, for the sake of readability  
and helpfulness to other programmers who read your code, using an  
obvious short form or the entire word is preferred (for me; your mileage  
may vary).

- Michael B.

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<div class="post-metadata">

**Author:** ![StecklyS\_Ron](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/dfb087/32.png) [@StecklyS\_Ron](https://www.ruby-forum.com/u/StecklyS_Ron)\
**Post date:** [December 8, 2007, 2:16am UTC](https://www.ruby-forum.com/t/completely-dumb-iterator-question-from-a-newbie/122485/3 "2007-12-08T02:16:31Z")

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Steckly, Ron wrote:

> inbox.Items.each do |message|  
> message.Attachments.each do |attachment|  
> filename = “c:\attachments\#{attachment.FileName}”  
> attachment.SaveAsFile(filename)  
> File.delete(filename) if File.size(filename) \< 500000  
> end  
> end

…

> The thing that’s bothering me is where people decide the thing to  
> iterate over. How do you decide what to put between the pipes | |?

There’s no magic about the word “message”. It’s just a variable name.  
You get to pick it. The magic is that the each method goes through each  
(aha! that’s why it’s called “each”) element in inbox.Items and assigns  
the element to the variable you named between the pipes.

Of course, once you pick a name to use you have to use it consistently.  
If you used “msg” between the pipes, you have to use “msg” instead of  
“message” throughout the code between do and end.