# How to manipulate a Hash object to String

**URL:** <https://www.ruby-forum.com/t/how-to-manipulate-a-hash-object-to-string/126502>\
**Category:** Ruby\
**Created:** [January 18, 2008, 7:36pm UTC](https://www.ruby-forum.com/t/how-to-manipulate-a-hash-object-to-string/126502 "2008-01-18T19:36:32Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Erwin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/a88e57/32.png) [@Erwin](https://www.ruby-forum.com/u/Erwin)\
**Post date:** [January 18, 2008, 7:36pm UTC](https://www.ruby-forum.com/t/how-to-manipulate-a-hash-object-to-string/126502/1 "2008-01-18T19:36:32Z")

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I got a result from my app (web service) that I transform into a  
Hash :

@return = Hash.from\_xml(data).values.first

@return = {“Saved”=\>“false”, “Rating”=\>{“Comment”=\>nil, “Error”=\>"  
missing"}, “Post”=\>{“Title”=\>nil, “Error”=\>“missing”},  
“Post”=\>{“Description”=\>nil, “Error”=\>“missing”},  
“XXX”=\>{“YYYYY”=\>nil, “ZZZZ”=\>“zzzzzz”}}

I would like to convert this result into a string , getting only the  
YYYYY: zzzzzz

like this one  
“Comment: missing, Title: missing, Description: missing, YYYYY:  
zzzzzz”

I am not very easy with Hash transformation, so a little bit help will  
be appreciated

thanks

Erwin

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<div class="post-metadata">

**Author:** ![Erwin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/a88e57/32.png) [@Erwin](https://www.ruby-forum.com/u/Erwin)\
**Post date:** [January 18, 2008, 8:04pm UTC](https://www.ruby-forum.com/t/how-to-manipulate-a-hash-object-to-string/126502/2 "2008-01-18T20:04:55Z")

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Erwin wrote:

> thanks
> 
> Erwin

It seems like you have some fairly specific data you need to put into  
the string, so I don’t think you can do this in a very generic way.

However, if you know what keys you need, then taking values from a hash  
and creating a string is pretty straightforward. I’m assuming here that  
you only want to display the “Error” when the other value doesn’t exist:

return\_string = “Comment: #{@return[“Rating”][“Comment”] ||  
@return[“Rating”][“Error”]}, Title: #{@return[“Post”][“Title”] ||  
@return[“Post”][“Error”]}” #…etc

But I noticed that you have two “Post” keys in your hash - one will  
overwrite the other. You might want to see what you are really getting  
back from the web service.

-Justin

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<div class="post-metadata">

**Author:** ![Erwin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/a88e57/32.png) [@Erwin](https://www.ruby-forum.com/u/Erwin)\
**Post date:** [January 21, 2008, 8:35am UTC](https://www.ruby-forum.com/t/how-to-manipulate-a-hash-object-to-string/126502/3 "2008-01-21T08:35:02Z")

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Erwin wrote:

> I got a result from my app (web service) that I transform into a  
> Hash :
> 
> @return = Hash.from\_xml(data).values.first
> 
> @return = {“Saved”=\>“false”, “Rating”=\>{“Comment”=\>nil, “Error”=\>"  
> missing"}, “Post”=\>{“Title”=\>nil, “Error”=\>“missing”},  
> “Post”=\>{“Description”=\>nil, “Error”=\>“missing”},  
> “XXX”=\>{“YYYYY”=\>nil, “ZZZZ”=\>“zzzzzz”}}

You seem to have more complex structure then just hash with single  
value. If you had simple hash you could do something like this.

c = ‘’  
@return.each\_pair {|k,v| c \<\< “#{k}: #{v},” }

You would also have to remove trailing ,

by  
TheR

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<div class="post-metadata">

**Author:** ![Erwin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/a88e57/32.png) [@Erwin](https://www.ruby-forum.com/u/Erwin)\
**Post date:** [January 21, 2008, 6:20pm UTC](https://www.ruby-forum.com/t/how-to-manipulate-a-hash-object-to-string/126502/4 "2008-01-21T18:20:48Z")

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Damjan R. wrote:

> c = ‘’  
> @return.each\_pair {|k,v| c \<\< “#{k}: #{v},” }
> 
> You would also have to remove trailing ,
> 
> by  
> TheR

irb(main):001:0\> {“1”=\>“2”, “3”=\>4}.map{|k,v| “#{k}:#{v}”}.join(",")  
=\> “1:2,3:4”  
irb(main):002:0\>

no trailing comma… 🙂

hth

ilan