From: Zach <zacharooni@...>
Date: 2006-01-24T03:36:17+09:00
Subject: Re: greetings

I may be totally off base, being a Ruby Newbie myself, but I believe the 
point of the :variable is sort of passing a HashMap to the method...for 
instance:

inside the method
    center = { :x => 1, :y => 2 }

you can refer to the parameters as :x and :y. As opposed to mandating 
the prototype of the method being center(x, y).

The benefits I can see are variable length arguments, and the arguments 
placed don't have to be in the same order. Coming from java, I'm 
actually a little wary about this, but I sort of understand the 
usefulness, especially after reading the Rails book.

-Zach


Mage wrote:

> Joe Van Dyk wrote:
>
>> On 1/23/06, Mage <mage@mage.hu> wrote:
>>  
>>
>>
>> The second edition of the book was released two years ago or so and
>> covers Ruby 1.8.  You should read that one instead.
>>
>> Here's a pretty good summary of the changes in Ruby 1.8. 
>> http://whytheluckystiff.net/articles/rubyOneEightOh.html
>>  
>>
> Thanx.
>
> One of the things I don't understand are the semicolons. When I read 
> the Book, it said:
>
> class SomeThing
>  atrr_reader :x, :y
> end
>
> I figured out that the attr_reader need to get the name of the 
> instance variables.
>
> However, what is this code good for?
>
> def make_point_hash( point )
>   center = { :x => 1, :y => 2 }
>   big = { :r => 10 }
>   center.merge( big ).merge( point ) end
> make_point_hash( { :x => 20 } )
>
> #=> {:y=>2, :r=>10, :x=>20}
>
> What is that those semicolons do?
>
>     Mage
>
>
>
>
>