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From: Amir Ebrahimifard on 3 Aug 2010 04:19
Hi
What does happen for "num" variable in this code :

array = [1,2,3,4,5]
x = 1
num = 1
array.each { |num| puts num*20 + x }

( after this code when I type "puts num , ruby return 5 ! why? )
--
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From: Eugen Ciur on 3 Aug 2010 04:41
|num| inside block iterates through array's items.
Last item in array is 5, thus |num| value will be the one from last
iteration of 'each' method.
It is better to rename |num| to something else, |item| for example.
-----
Eugen

On 08/03/2010 11:19 AM, Amir Ebrahimifard wrote:
> Hi
> What does happen for "num" variable in this code :
>
> array = [1,2,3,4,5]
> x = 1
> num = 1
> array.each { |num| puts num*20 + x }
>
> ( after this code when I type "puts num , ruby return 5 ! why? )
>

From: Guglielmo Fachini on 3 Aug 2010 04:53
Eugen Ciur wrote:
> |num| inside block iterates through array's items.
> Last item in array is 5, thus |num| value will be the one from last
> iteration of 'each' method.
> It is better to rename |num| to something else, |item| for example.
> -----
> Eugen

I've tried it in my machine and the output is 1...

C:\Users\Guglielmo>ruby -v
ruby 1.9.1p378 (2010-01-10 revision 26273) [i386-mingw32]

C:\Users\Guglielmo>ruby
array = [1,2,3,4,5]
x = 1
num = 1
array.each { |num| puts num*20 + x }
puts num
^D
21
41
61
81
101
1
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From: Eugen Ciur on 3 Aug 2010 05:02
Look here
http://svn.ruby-lang.org/repos/ruby/tags/v1_9_1_0/NEWS

Since v 1.9.1 block arguments (in our case |num|) are always local,
i.e in 'each' block |num| will not conflict
with outer 'num' variable. In your machine you have 1.9.1 version.

On 08/03/2010 11:53 AM, Guglielmo Fachini wrote:
> Eugen Ciur wrote:
>
>> |num| inside block iterates through array's items.
>> Last item in array is 5, thus |num| value will be the one from last
>> iteration of 'each' method.
>> It is better to rename |num| to something else, |item| for example.
>> -----
>> Eugen
>>
> I've tried it in my machine and the output is 1...
>
> C:\Users\Guglielmo>ruby -v
> ruby 1.9.1p378 (2010-01-10 revision 26273) [i386-mingw32]
>
> C:\Users\Guglielmo>ruby
> array = [1,2,3,4,5]
> x = 1
> num = 1
> array.each { |num| puts num*20 + x }
> puts num
> ^D
> 21
> 41
> 61
> 81
> 101
> 1
>

-----
Eugen

From: Amir Ebrahimifard on 3 Aug 2010 05:45
Eugen Ciur wrote:
> Look here
> http://svn.ruby-lang.org/repos/ruby/tags/v1_9_1_0/NEWS
>
> Since v 1.9.1 block arguments (in our case |num|) are always local,
> i.e in 'each' block |num| will not conflict
> with outer 'num' variable. In your machine you have 1.9.1 version.

It means in ruby v 1.8.6 block variable and local variable are the same
, and not difference between them ?
--
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