From: "Erik Bågfors" <erik@...>
Date: 2001-03-06T20:57:20+09:00
Subject: [ruby-talk:12118] Re: String.gsub()

On 06 Mar 2001 20:50:24 +0900, Mike Bowler wrote:
> The method String.gsub() isn't working the way I expected (or the way
> the pickaxe book describes it for that matter).  Given this code:
> 
> def replaceSingleQuotesWithDouble( inputString )
>    puts "original="+inputString
> 
>    puts inputString.gsub(/'(.+)'/, "\"\1\"")
> end
> 
> replaceSingleQuotesWithDouble("foo 'bar' foo")
> 
> I would expect the output to be
> 
>     foo "bar" foo
> 
> Instead I get
> 
>     foo "" bar
> 
> The match is successful but it seems that the variable \1 hasn't been
> assigned by the time we are doing the substitution.
> 
> Am I doing something wrong?
> 

I fell for that too.

if you use " around the \1 you need to escape the \ with another \.

so... change the gsub line to either
puts inputString.gsub(/'(.+)'/, "\"\\1\"")
or
puts inputStrng.gsub(/'(+)'/, '"\1"')

Where the second one is alot easier since you don't have to escape the "

/Erik

-- 
Erik B�gfors               | http://erik.bagfors.nu/    
erik@bagfors.nu            | Erik.Bagfors@engohol.se
Supporter of free software | GSM +46 733 279 273
fingerprint: 6666 A85B 95D3 D26B 296B 6C60 4F32 2C0B 693D 6E32