# I need some help clarifying issues with YAML and hashes

**URL:** <https://www.ruby-forum.com/t/i-need-some-help-clarifying-issues-with-yaml-and-hashes/107805>\
**Category:** Ruby\
**Created:** [June 26, 2007, 1:21pm UTC](https://www.ruby-forum.com/t/i-need-some-help-clarifying-issues-with-yaml-and-hashes/107805 "2007-06-26T13:21:03Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![vfcforums](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/85e7bf/32.png) [@vfcforums](https://www.ruby-forum.com/u/vfcforums)\
**Post date:** [June 26, 2007, 1:21pm UTC](https://www.ruby-forum.com/t/i-need-some-help-clarifying-issues-with-yaml-and-hashes/107805/1 "2007-06-26T13:21:03Z")

</div>

The code below, config.yml and testvars.rb are supposed to created some  
arrays and hashes.

When I assign the directory1 and directory2 hashes directly into  
dirArray :

dirname.each { | k | dirArray = k }

dirArray doesn’t contains the keys “directory1” and “directory2”, which  
is what I expect

but when I assign them via key = value

dirname.each { | k | k.each {| l, m | dirArray[l]=m } }

dirArray contains the keys “directory1” and “directory2”

I know my grasp of ruby semantics is not up to scratch yet, but is it a  
YAML issue or a Ruby issue?

# config4.yml

directories :  
directory1 :  
directory : /thisdirectory/yada/yada/yada  
archivename : archivename01  
configdir : configdir01  
workdir : workingdir01  
logsdir : logsdir01

```
directory2 :
   directory : /thisdirectory/yada2/yada2/yada2
   archivename : archivename02
   configdir : configdir02
   workdir : workingdir02
   logsdir : logsdir02

```

# Code - testvars4.rb

require ‘yaml’

config = YAML::load(File.open(‘config4.yml’))

puts “assign via hash directly\n”  
puts “”

dirArray = Hash.new  
config[“directories”].each { | dirname |  
puts “”

dirname.each { | k | dirArray = k }

puts “dirArray elements start = \n”  
puts “”  
dirArray.each { | l, m | puts “#{l} =\> #{m}” }  
puts “”  
puts “dirArray elements end= \n”

}  
puts “”  
puts “assign via | key = val | \n”  
puts

dirArray = Hash.new  
config[“directories”].each { | dirname |

dirname.each { | k | k.each {| l, m | dirArray[l]=m } }

puts “dirArray elements start = \n”  
puts “”  
dirArray.each { | l, m | puts “#{l} =\> #{m}” }  
puts “”  
puts “dirArray elements end= \n”  
puts “”  
}

# Output

assign via hash directly

dirArray elements start =

directory =\> /thisdirectory/yada/yada/yada  
configdir =\> configdir01  
workdir =\> workingdir01  
archivename =\> archivename01  
logsdir =\> logsdir01

dirArray elements end=

dirArray elements start =

directory =\> /thisdirectory/yada2/yada2/yada2  
configdir =\> configdir02  
workdir =\> workingdir02  
archivename =\> archivename02  
logsdir =\> logsdir02

dirArray elements end=

assign via | key = val |

dirArray elements start =

directory =\> /thisdirectory/yada/yada/yada  
configdir =\> configdir01  
archivename =\> archivename01  
workdir =\> workingdir01  
logsdir =\> logsdir01  
directory1 =\>

dirArray elements end=

dirArray elements start =

directory =\> /thisdirectory/yada2/yada2/yada2  
configdir =\> configdir02  
archivename =\> archivename02  
workdir =\> workingdir02  
logsdir =\> logsdir02  
directory1 =\>  
directory2 =\>

dirArray elements end=

---

<div class="post-metadata">

**Author:** ![vfcforums](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/85e7bf/32.png) [@vfcforums](https://www.ruby-forum.com/u/vfcforums)\
**Post date:** [June 26, 2007, 3:04pm UTC](https://www.ruby-forum.com/t/i-need-some-help-clarifying-issues-with-yaml-and-hashes/107805/2 "2007-06-26T15:04:31Z")

</div>

On 6/26/07, Frank C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> The code below, config.yml and testvars.rb are supposed to created some  
> arrays and hashes.

Your YAML is all hashes; there are no arrays.

> When I assign the directory1 and directory2 hashes directly into  
> dirArray :
> 
> dirname.each { | k | dirArray = k }

dirname is a Hash, with two entries that are themselves hashes. When  
you call each() on a Hash, you get a 2-element (key, value) array. So  
k is an array, not a hash.

What are you trying to do?

> dirArray doesn’t contains the keys “directory1” and “directory2”, which  
> is what I expect
> 
> but when I assign them via key = value
> 
> dirname.each { | k | k.each {| l, m | dirArray[l]=m } }
> 
> dirArray contains the keys “directory1” and “directory2”

Yes, given what k is.

> I know my grasp of ruby semantics is not up to scratch yet, but is it a  
> YAML issue or a Ruby issue?

I’m guessing it’s related to your misconception of what the YAML is  
actually representing.

Use some calls to p() to dump some of these structures so you can see  
what you’re dealing with.