From: Calvin Bornhofen <calvin.bornhofen@...>
Date: 2012-09-22T00:16:53+09:00
Subject: Re: Class variables

> How about:
>
>   class Foo
>     def self.suits
>       @suits ||= %w(C D H S)
>     end
>   end
>
Works too. If you just wanted to read the variable or perform actions 
with it, that is definitely shorter.
> or even just
>
>   class Foo
>     def self.suits
>       %w(C D H S)
>     end
>   end
Looks similar, but it has one flaw: The array is created every time 
again the method is called ( checked via object_id - it differs every 
time the method is called ). Might not make a difference in this 
scenario, but if you wanted to modify the array, your changes wouldn't 
persist. So that's something to be aware of. It can also be a 
performance problem if the array gets more complex, I think.