From: "David A. Black" <dblack@...>
Date: 2005-07-26T02:25:55+09:00
Subject: Re: Newby question 'unless'

Hi --

On Tue, 26 Jul 2005, Patrick Gundlach wrote:

> Hi,
>
>> def to_s
>>    "#{@a}" + "#{@b}" unless @a == 0
>> end
>
>  def to_s
>   "#{@a}" +  (@a == 0 ? "" : "#{@b}" )
>  end

Conditionals give you nil when they're not met, and nil.to_s is an
empty string, so you don't have to specify a literal empty string in
cases like this.  I would refactor your second line to:

    "#{@a}" +  ("#{@b}" unless @a.zero?)

at which point you can make it nicer by getting rid of the parens and
the + :

    "#{@a}#{@b unless @a.zero?}"

That gives you a closer lexical mapping between what you're asking for
and how the eventually string will read ("@a@b?", one might say).


David

-- 
David A. Black
dblack@wobblini.net