From: Ken Bloom <kbloom@...>
Date: 2008-04-19T05:10:08+09:00
Subject: Re: Why this code is working

On Fri, 18 Apr 2008 14:29:10 -0500, Neeraj Kumar wrote:

> this code is a simplified version of the code I saw in Rails.
> 
> def speak(*types,&block)
>   block.call
> end
> 
> # I can understand why this code is working speak(23) { puts 'hi' }
> 
> # why this code is working ?. This code should fail because I am not
> providing any # param to types. It means block is being passed as the
> first param and that's not # good
> speak { puts 'hi' }

When you prefix the last argument name with a * (as you did with *types) 
then you can have any number of arguments (0 or more) at the end, and 
they will all be put into an array.

so

def speak(*types,&block)
  p types
  block.call
end

speak(23) { puts 'hi' }
speak { puts 'hi' }

will print

[23]
hi
[]
hi




-- 
Ken (Chanoch) Bloom. PhD candidate. Linguistic Cognition Laboratory.
Department of Computer Science. Illinois Institute of Technology.
http://www.iit.edu/~kbloom1/