Rails - Mar 2006 - string interpolation - #{} vs. single vs. double quotes

Could someone point me to documentation that provides a succinct and accurate
description of the difference between interpolation using #{}, single quotes,
and double quotes ?

I imagine there''s a set of precedence rules that govern behavior
if/when they''re mixed.  I''d like to get clear on this.

Thanks,
Bill
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In short:

Double quotes and heredoc evaluate #{}
SIngle quotes do not evaluate

http://www.rubycentral.com/book/tut_stdtypes.html#S2

Regards,

?ukasz

On 31/03/06, Bill Walton <bill.walton@charter.net>
wrote:
>
> Could someone point me to documentation that provides a succinct and
> accurate description of the difference between interpolation using #{},
> single quotes, and double quotes ?
>
> I imagine there''s a set of precedence rules that govern behavior
if/when
> they''re mixed.  I''d like to get clear on this.
>
> Thanks,
>
> Bill
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
>
>

--
?ukasz Piestrzeniewicz
http://ragnarson.blogspot.com

http://www.rubycentral.com/book/tut_stdtypes.html
http://www.rubycentral.com/book/language.html

would be a good place to start.

On 3/31/06, Bill Walton <bill.walton@charter.net>
wrote:
>
> Could someone point me to documentation that provides a succinct and
> accurate description of the difference between interpolation using #{},
> single quotes, and double quotes ?
>
> I imagine there''s a set of precedence rules that govern behavior
if/when
> they''re mixed.  I''d like to get clear on this.
>
> Thanks,
> Bill
>
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
>
>
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Thank you, Chris.  That''s exactly what I was looking for.  

The lack of an index on the Ruby PDF drives me nuts.  How do you find this
stuff?

Best regards,
Bill
  ----- Original Message ----- 
  From: Chris Hall 
  To: rails@lists.rubyonrails.org 
  Sent: 2006-03-31 10:10 AM
  Subject: Re: [Rails] string interpolation - #{} vs. single vs. double quotes


  http://www.rubycentral.com/book/tut_stdtypes.html
  http://www.rubycentral.com/book/language.html 

  would be a good place to start.


  On 3/31/06, Bill Walton <bill.walton@charter.net> wrote: 
    Could someone point me to documentation that provides a succinct and
accurate description of the difference between interpolation using #{}, single
quotes, and double quotes ?

    I imagine there''s a set of precedence rules that govern behavior
if/when they''re mixed.  I''d like to get clear on this.

    Thanks,
    Bill

    _______________________________________________
    Rails mailing list
    Rails@lists.rubyonrails.org 
    http://lists.rubyonrails.org/mailman/listinfo/rails







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  _______________________________________________
  Rails mailing list
  Rails@lists.rubyonrails.org
  http://lists.rubyonrails.org/mailman/listinfo/rails
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Thanks, Lukasz.  I appreciate the help.  I was hoping there was a short
answer.  In reading the doc (now that you and Chris have helped me find it)
it seems that I may need to explain (I''m working on a tutorial) the
diff
between ''evaluate'' and ''substitute'' since
single quotes do do some
substitution.  Or maybe I''ll just say something like "In case A,
use x.  In
case B, use y.  In case C, buy the book."  ;-)

Thanks again,
Bill

----- Original Message -----
From: "?ukasz Piestrzeniewicz" <bragi.ragnarson@gmail.com>
To: <rails@lists.rubyonrails.org>
Sent: 2006-03-31 10:09 AM
Subject: Re: [Rails] string interpolation - #{} vs. single vs. double quotes

> In short:
>
> Double quotes and heredoc evaluate #{}
> SIngle quotes do not evaluate
>
> http://www.rubycentral.com/book/tut_stdtypes.html#S2
>
> Regards,
>
> ?ukasz
>
> On 31/03/06, Bill Walton <bill.walton@charter.net> wrote:
> >
> > Could someone point me to documentation that provides a succinct and
> > accurate description of the difference between interpolation using
#{},
> > single quotes, and double quotes ?
> >
> > I imagine there''s a set of precedence rules that govern
behavior if/when
> > they''re mixed.  I''d like to get clear on this.
> >
> > Thanks,
> >
> > Bill
> > _______________________________________________
> > Rails mailing list
> > Rails@lists.rubyonrails.org
> > http://lists.rubyonrails.org/mailman/listinfo/rails
> >
> >
> >
>
>
> --
> ?ukasz Piestrzeniewicz
> http://ragnarson.blogspot.com
>

----------------------------------------------------------------------------
----

> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>

?ukasz Piestrzeniewicz wrote:
> Double quotes and heredoc evaluate #{}
Here documents can follow single-quote rules, if you single-quote the 
here string (if that''s what it''s called) at the start:

question = <<''ENDQ''
Could someone point me to documentation that provides a
succinct and accurate description of the difference between 
interpolation using #{}, single quotes, and double quotes ?
ENDQ

Try this in IRB, and you''ll get:
=> "Could someone point me to documentation that provides a\nsuccinct 
and accurate description of the difference between interpolation using 
\#{}, single quotes, and double quotes ?\n"

regards

   Justin

On 31 Mar 2006, at 18:32, Bill Walton wrote:
> Thank you, Chris.  That''s exactly what I was looking for.
>
> The lack of an index on the Ruby PDF drives me nuts.  How do you  
> find this stuff?
>
I''d recommend the Ruby for Rails book, all things make so much sense  
afterwards. The agile web development book is great, but you never  
learn the underpinnings of Rails.


Best regards

Peter De Berdt