# Inexistent instance variable value

**URL:** <https://www.ruby-forum.com/t/inexistent-instance-variable-value/173154>\
**Category:** Ruby\
**Created:** [August 4, 2009, 6:24am UTC](https://www.ruby-forum.com/t/inexistent-instance-variable-value/173154 "2009-08-04T06:24:22Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Ricardo\_Amorim](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/9dc877/32.png) [@Ricardo\_Amorim](https://www.ruby-forum.com/u/Ricardo_Amorim)\
**Post date:** [August 4, 2009, 6:24am UTC](https://www.ruby-forum.com/t/inexistent-instance-variable-value/173154/1 "2009-08-04T06:24:22Z")

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Howdy,

I have noticed this a while ago and someone asked in IRC, and I have  
no clue on WHY this happens:

irb(main):001:0\> local\_var  
NameError: undefined local variable or method `local\_var’ for  
main:Object  
from (irb):1  
irb(main):002:0\> @local\_var  
=\> nil

Why are instance\_variables always available as nil when not defined?

Regards,

Ricardo Amorim  
[mapaBRASIL.net](http://mapaBRASIL.net)

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<div class="post-metadata">

**Author:** ![Ricardo\_Amorim](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/9dc877/32.png) [@Ricardo\_Amorim](https://www.ruby-forum.com/u/Ricardo_Amorim)\
**Post date:** [August 6, 2009, 4:08pm UTC](https://www.ruby-forum.com/t/inexistent-instance-variable-value/173154/2 "2009-08-06T16:08:33Z")

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Ricardo Amorim wrote:

> Why are instance\_variables always available as nil when not defined?
> 
> Regards,

It is by design.

[http://www.rubyist.net/~slagell/ruby/instancevars.html](http://www.rubyist.net/~slagell/ruby/instancevars.html)

## Regards wisccal

www.skre.ch