From: Robert Dober <robert.dober@...>
Date: 2007-07-20T20:25:14+09:00
Subject: Re: Is there a replacement for sub?

On 7/20/07, Michael W. Ryder <_mwryder@worldnet.att.net> wrote:
> I was trying to come up with a way to remove x instances of a character
> from a string and came up with a problem.  If I enter:
>
> a = "a b c d e f"
> for i in 1..3
>    a = a.sub!(' ', '')
> end
> puts a  ==> returns 'abcd e f' which is correct.
>
> But if I enter:
>
> a = "a b c d e f"
> for i in 1..10
>    a = a.sub!(' ', '')
> end
> puts a  ==> returns error.rb:3: private method `sub!' called for
> nil:NilClass (NoMethodError, and a is now nil.
>
> What I am looking for is a way to remove the first n instances of a
> blank from the string without wiping out the string if it does not
> contain at least n blanks.  I assume there is a way to do this with
> regular expressions, but have not found it yet.  This is something an
> editor I liked, UCEDIT, on the CDC Cyber had in the 70's.
>
>

I was reading this whole thread and I kind of think to be dreaming, I
must have missed something obvious!!!
Anyway maybe this is was OP wants, well I think it is ;)

529/29 > irb
irb(main):001:0> a='a b c d e f'
=> "a b c d e f"
irb(main):002:0> a.gsub!(" ","")
=> "abcdef"
irb(main):003:0> a
=> "abcdef"
irb(main):004:0>

Consider however using the non inplace version, like e.g.

b = a.gsub(" ","")

HTH
Robert

-- 
I always knew that one day Smalltalk would replace Java.
I just didn't know it would be called Ruby
-- Kent Beck