From: repeater <repeater@...>
Date: 2002-04-03T18:20:27+09:00
Subject: RE: rcr

> -----Original Message-----
> From: Paul Duncan [mailto:pabs@pablotron.org]
> Sent: 03 April 2002 06:26
> To: ruby-talk ML
> Subject: Re: rcr
>
> * repeater (repeater@lucentprimate.cjb.net) wrote:
> > i've not used ruby for that long, but i've found the need to do the
> > following rather often:
> >
> > [3, 2, 5, 2, 19].rand_item		# => returns random item from array
> >
> > short code, but could be helpful to others (needed it in all of my last
> > projects, but perhaps i'm just strange)
>
> Were you asking for code to return a random element, or saying you have
> code that returns a random element?  If it's the latter, here's a
> quick answer:
>
> --
> class Array
>   def rand
>     raise RuntimeError, 'Array#rand(): empty array' unless length > 0
>     at Kernel::rand(length).floor
>   end
> end
>
> # test Array#rand()
> arr = %w(asdf hey matz ruby rocks test 123)
> 4.times { puts arr.rand }
> [].rand
> --
>
> produces (for this particular run):
> hey
> matz
> rocks
> hey
> ./array_random.rb:5:in `rand': Array#rand(): empty array (RuntimeError)
>         from ./array_random.rb:15
>

thanks, i've got code but forgot to post it (though i learnt a few things
from yours !)

is this too specialised for a RCR ? hopefully people will not consider it
equally silly as retreiving an item according to a digit of Pi (therefore:
"write your own arr.pi_item, damnit!"). i would expect if to be part of
Array, and i needed it suspiciously often the last few weeks.

perhaps i'm a bit hasty, basing my request on my limited experience :-) so
my apologies if this is so
regards
repeater