From: vjoel@...
Date: 2001-10-28T11:55:59+09:00
Subject: [ruby-talk:23659] Re: How to get a String to interpolate itself?

Phil Tomson wrote:
> 
> I'm trying to read lines from a file that might contain something like:
> 
> Here is a line with a variable to interpolate: #{var}
> 
> Now when I read it in like:
> 
>   var = 99
>   File.foreach("junk.rbt") {|line|
>     puts line
>   }
> 
> of course I get the same line in the file with the #{var} in it.
> I'd like to get:
> Here is a line with a variable to interpolate: 99
> 
> I suspect there must be a way to do this since using "" causes
> interpolation, how can I get an existing String to interpolate itself?
> 
> Phil

How's this?

 var = 3
 str = 'This is the value of var: #{var}'
 puts eval "\"#{str}\""
 # ==> This is the value of var: 3

 # also:
 puts eval '"' + str + '"'
 # ==> This is the value of var: 3

--
Joel VanderWerf                          California PATH, UC Berkeley
mailto:vjoel@path.berkeley.edu                     Ph. (510) 231-9446
http://www.path.berkeley.edu                       FAX (510) 231-9512