From: Axel Etzold <AEtzold@...>
Date: 2007-11-15T20:24:45+09:00
Subject: Re: Array checking ????????????????????


-------- Original-Nachricht --------
> Datum: Thu, 15 Nov 2007 19:51:58 +0900
> Von: "David A. Black" <dblack@rubypal.com>
> An: ruby-talk@ruby-lang.org
> Betreff: Re: Array checking ????????????????????

> Hi --
> 
> On Thu, 15 Nov 2007, Axel Etzold wrote:
> 
> >
> > -------- Original-Nachricht --------
> >> Datum: Thu, 15 Nov 2007 18:59:07 +0900
> >> Von: Nadeesha Meththananda <neranjan125@gmail.com>
> >> An: ruby-talk@ruby-lang.org
> >> Betreff: Array checking ????????????????????
> >
> >>
> >>
> >> hi
> >>
> >> i have written a array like this.
> >>
> >> my_array = ["one","two","three","four"]
> >>
> >> no i want to check a given string is can be found from the above array.
> >>
> >> eg:
> >>
> >>          if  ( my_array.map{"one"} )
> >>            return true;
> >>          else
> >>           return false;
> >>           end
> >>
> >>
> >> so here if i use "five" insted of "one" it should return false( as i
> >> think) but it does no happen.
> >>
> >> (simply want to check a given string is in the array or not)
> >>
> >> so if any body can help????
> >> --
> >> Posted via http://www.ruby-forum.com/.
> >
> > Dear Nadeesha,
> >
> > you can use
> >
> > class Array
> >    def contains_entry?(entry)
> >       if self-[entry]==self
> >              return false
> >       else
> >              return true
> >      end
> >      end
> > end
> >
> > a=["one","two",3,4]
> > p a.contains_entry?("three")
> >
> > The idea is to see whether the array stays the same when you take
> > away something from it - if yes, that something wasn't in the array
> > in the first place.
> 
> No, you definitely don't want to do that, for many reasons. As Jari
> said, just use include?
> 
>    if array.include?(entry)
> 
> 
> David
> 
> -- 
> Upcoming training by David A. Black/Ruby Power and Light, LLC:
>    * Advancing With Rails, Berlin, Germany, November 19-22
>    * Intro to Rails, London, UK, December 3-6 (by Skills Matter)
> See http://www.rubypal.com for details!

Dear Nadeesha,

indeed, Jari's solution is way better. Shorter, more elegant.
I wouldn't have written
a post had Jari's response already been on the list.


Best regards,

Axel 


-- 
Psssst! Schon vom neuen GMX MultiMessenger geh�rt?
Der kann`s mit allen: http://www.gmx.net/de/go/multimessenger