From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2008-11-05T17:44:15+09:00
Subject: Re: Double characters in string

On Wed, Nov 5, 2008 at 8:53 AM, Wouss Bla <wvdongen@zonnet.nl> wrote:
> Hi,
>
> I'm looking for a way to put a 'X' between all double characters in a
> string. So if this would be the string: 'hello, I just said hello' would
> be changed into 'helXlo, I just said helXlo'.
>
> I tried:
>
> text = text.sub(/([a-z])\1/,'\1x\1')
>
> But this only changed the first double character...

From ri:

------------------------------------------------------------- String#sub
     str.sub(pattern, replacement)         => new_str
     str.sub(pattern) {|match| block }     => new_str
------------------------------------------------------------------------
     Returns a copy of _str_ with the _first_ occurrence of _pattern_
     replaced with either _replacement_ or the value of the block.

So it only replaces the first occurrence. Try gsub:

------------------------------------------------------------ String#gsub
     str.gsub(pattern, replacement)       => new_str
     str.gsub(pattern) {|match| block }   => new_str
------------------------------------------------------------------------
     Returns a copy of _str_ with _all_ occurrences of _pattern_
     replaced with either _replacement_ or the value of the block


irb(main):001:0> "hello, I said hello".gsub(/([a-z])\1/,'\1x\1')
=> "helxlo, I said helxlo"

Jesus.