From: "Iñaki Baz Castillo" <ibc@...>
Date: 2010-01-08T18:49:42+09:00
Subject: Re: when to use * arguments?

El Viernes, 8 de Enero de 2010, Zhenning Guan escribió:
> version one:
> 
> def say(*a)
>   a.each {|r| puts r }
> end
> 
> say(1,2,3)
> ------
> 
> version two:
> 
> def say(a)
>   a.each {|r| puts r }
> end
> 
> say([1,2,3])
> -------
> So, any different here? when should we * arguments like version one?

* is useful when you don't know the number and kind of arguments the method 
will receive. Using * will convert any arguments to an Array.

In your first version:

  irb> say 123
  123
  [123] <-- returns an Array

In your second version:

   irb> say 123
   NoMethodError: undefined method `each' for 2:Fixnum
        from (irb):6:in `say'
  


-- 
Iñaki Baz Castillo <ibc@aliax.net>