From: twifkak@...
Date: 2005-07-20T04:04:20+09:00
Subject: Re: Regarding rand

I like it! Two notes:

1. Use #respond_to? instead of ::method_defined? This allows for singleton methods.*

2. What other people are saying about the cost of creating an array each time. You might use each_with_index (which is stupidly slow for Arrays), or might implement a different rand method for Range, Array, etc.

Devin

> I was reading Learn to Program by Chris Pine yesterday, in one bit it says:
> 	' Note that I used rand(101) to get back numbers from 0  to 100, and
> that rand(1) always gives back 0.'
> 
> I was wondering if rand() could support syntax like:
>    rand(0..100)
> 
> Here's my go:
> 
> def random(value)
> 	if value.class.method_defined? 'entries'
> 		entries = value.entries
> 		entries[rand(entries.length)]
> 	else
> 		rand(value)
> 	end
> end
> 
> this works with arrays and hashes too.
> 
> I'm coming to Ruby via RoR and i'm loving it, I should be writing a
> web app and i'm playing with Ruby instead.
> 
> Ben
>