# Scope issue of variable in iterator

**URL:** <https://www.ruby-forum.com/t/scope-issue-of-variable-in-iterator/85398>\
**Category:** Ruby\
**Created:** [March 22, 2006, 5:41pm UTC](https://www.ruby-forum.com/t/scope-issue-of-variable-in-iterator/85398 "2006-03-22T17:41:48Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Mohammad\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/8e8cbc/32.png) [@Mohammad\_K](https://www.ruby-forum.com/u/Mohammad_K)\
**Post date:** [March 22, 2006, 5:41pm UTC](https://www.ruby-forum.com/t/scope-issue-of-variable-in-iterator/85398/1 "2006-03-22T17:41:48Z")

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mkhan@mkhan:~$ irb  
irb(main):001:0\> batman = ‘robin’  
=\> “robin”  
irb(main):002:0\> [‘cat’, ‘dog’, ‘horse’, ‘chicken’].each { |batman|  
puts batman }  
cat  
dog  
horse  
chicken  
=\> [“cat”, “dog”, “horse”, “chicken”]  
irb(main):003:0\> puts “Now you might think this would say ‘robin’, but  
it says: #{batman}”  
Now you might think this would say ‘robin’, but it says: chicken  
=\> nil  
irb(main):004:0\>

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**Author:** ![Mohammad\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/8e8cbc/32.png) [@Mohammad\_K](https://www.ruby-forum.com/u/Mohammad_K)\
**Post date:** [March 22, 2006, 5:48pm UTC](https://www.ruby-forum.com/t/scope-issue-of-variable-in-iterator/85398/2 "2006-03-22T17:48:06Z")

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On 3/22/06, Mohammad K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> irb(main):003:0\> puts “Now you might think this would say ‘robin’, but  
> it says: #{batman}”  
> Now you might think this would say ‘robin’, but it says: chicken  
> =\> nil

It’s true that blocks introduce a new scope.  
However, if they use variables that are in scope outside the block,  
they don’t shadow those variables, they use them.

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**Author:** ![Mohammad\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/8e8cbc/32.png) [@Mohammad\_K](https://www.ruby-forum.com/u/Mohammad_K)\
**Post date:** [March 22, 2006, 7:04pm UTC](https://www.ruby-forum.com/t/scope-issue-of-variable-in-iterator/85398/3 "2006-03-22T19:04:41Z")

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Mark V. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> > =\> [“cat”, “dog”, “horse”, “chicken”]  
> > irb(main):003:0\> puts “Now you might think this would say ‘robin’,  
> > but it says: #{batman}”  
> > Now you might think this would say ‘robin’, but it says: chicken  
> > =\> nil
> 
> It’s true that blocks introduce a new scope.  
> However, if they use variables that are in scope outside the block,  
> they don’t shadow those variables, they use them.

… like in other programming languages as well.

```
robert

```