# Why is not work?

**URL:** <https://www.ruby-forum.com/t/why-is-not-work/109851>\
**Category:** Ruby\
**Created:** [July 19, 2007, 5:13pm UTC](https://www.ruby-forum.com/t/why-is-not-work/109851 "2007-07-19T17:13:36Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![bkeh12](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/7993a0/32.png) [@bkeh12](https://www.ruby-forum.com/u/bkeh12)\
**Post date:** [July 19, 2007, 5:13pm UTC](https://www.ruby-forum.com/t/why-is-not-work/109851/1 "2007-07-19T17:13:36Z")

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Hi all,

module A  
end  
A.autoload(:B, “b”)  
A::B.doit # autoloads “b”

result :  
uninitialized constant A::B (NameError)

---

<div class="post-metadata">

**Author:** ![bkeh12](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/7993a0/32.png) [@bkeh12](https://www.ruby-forum.com/u/bkeh12)\
**Post date:** [July 19, 2007, 5:30pm UTC](https://www.ruby-forum.com/t/why-is-not-work/109851/2 "2007-07-19T17:30:09Z")

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On 7/19/07, Chung C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> Hi all,
> 
> module A  
> end  
> A.autoload(:B, “b”)  
> A::B.doit # autoloads “b”
> 
> result :  
> uninitialized constant A::B (NameError)

Do you have a file named “b”?

---

<div class="post-metadata">

**Author:** ![bkeh12](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/7993a0/32.png) [@bkeh12](https://www.ruby-forum.com/u/bkeh12)\
**Post date:** [July 20, 2007, 2:36am UTC](https://www.ruby-forum.com/t/why-is-not-work/109851/3 "2007-07-20T02:36:28Z")

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Todd B. wrote:

> On 7/19/07, Chung C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:
> 
> > Hi all,
> > 
> > module A  
> > end  
> > A.autoload(:B, “b”)  
> > A::B.doit # autoloads “b”
> > 
> > result :  
> > uninitialized constant A::B (NameError)
> 
> Do you have a file named “b”?

Hi,

Yes, I have.

A.autoload?(:B) # “b”

---

<div class="post-metadata">

**Author:** ![bkeh12](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/7993a0/32.png) [@bkeh12](https://www.ruby-forum.com/u/bkeh12)\
**Post date:** [July 20, 2007, 3:12am UTC](https://www.ruby-forum.com/t/why-is-not-work/109851/4 "2007-07-20T03:12:48Z")

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Chung C. wrote:

> Todd B. wrote:
> 
> > On 7/19/07, Chung C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:
> > 
> > > Hi all,
> > > 
> > > module A  
> > > end  
> > > A.autoload(:B, “b”)  
> > > A::B.doit # autoloads “b”
> > > 
> > > result :  
> > > uninitialized constant A::B (NameError)
> > 
> > Do you have a file named “b”?
> 
> Hi,
> 
> Yes, I have.
> 
> A.autoload?(:B) # “b”

irb(main):001:0\> module A  
irb(main):002:1\> end  
=\> nil  
irb(main):003:0\> A.autoload(:B,“b”)  
=\> nil  
irb(main):004:0\> A.autoload?(:B)  
=\> “b”  
irb(main):005:0\> A::B.hello  
NameError: uninitialized constant A::B  
from (irb):5  
irb(main):006:0\> require “b”  
=\> false  
irb(main):007:0\> B.hello  
“hello”  
=\> nil

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<div class="post-metadata">

**Author:** ![bkeh12](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/7993a0/32.png) [@bkeh12](https://www.ruby-forum.com/u/bkeh12)\
**Post date:** [July 20, 2007, 5:32am UTC](https://www.ruby-forum.com/t/why-is-not-work/109851/5 "2007-07-20T05:32:43Z")

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Hi,

At Fri, 20 Jul 2007 10:12:47 +0900,  
Chung C. wrote in [ruby-talk:260876]:

> irb(main):006:0\> require “b”  
> =\> false  
> irb(main):007:0\> B.hello  
> “hello”  
> =\> nil

Seems b.rb defines ::B but doesn’t A::B.