From: Florian Gilcher <flo@...>
Date: 2009-11-28T12:15:43+09:00
Subject: Re: where is grep?

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Grep is not defined on Ruby 1.9-Strings.

It was on Ruby 1.8-Strings, but only because they were belonging to  
the group of objects that mixed in Enumerable.

There, grep behaves like this (line by line):

   x = "hello world baby girl"
   x.grep(/hello/)
   #=> ["hello world baby girl"]
   x = "hello\nworld\nbaby\ngirl"
   x.grep(/hello/)
   #=> ["hello\n"]

The same can be done in Ruby 1.9 by just splitting the String  
beforehand. Arrays are Enumerable and thus
still have grep:

   x = "hello\nworld\nbaby\ngirl"
   x.split("\n").grep(/hello/)
   #=> ["hello"]

Note the absence of the line-break which might be intended or not :).

Regards,
Florian Gilcher

On Nov 27, 2009, at 11:26 PM, Ruby Newbee wrote:

> Hello,
>
> I tried to grep from a string, but got wrong.
>
> irb(main):010:0* x = "hello world baby girl"
> => "hello world baby girl"
> irb(main):011:0>
> irb(main):012:0*
> irb(main):013:0* x.grep(/hello/)
> NoMethodError: undefined method `grep' for "hello world baby  
> girl":String
>        from (irb):13
>        from /usr/bin/irb:12:in `<main>'
>
>
>
> where shall 'grep' method come from?
>
> thanks~
>

- --
Florian Gilcher

smtp:   flo@andersground.net
jabber: Skade@jabber.ccc.de
gpg:    533148E2

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