#class variables

[darshecodes]

Class vs Instance Variables

ONCE AND FOR ALL LETS DEFINE THIS

class variable

When you set a class variable, you set it for the superclass and all of the subclasses.

class RoadSigns

@@sign = 'stop'

end

puts RoadSigns.sign #=> 'stop'

~~~~~~~~~~~~~~~~~~~

class TheseSigns < RoadSigns

@@sign = 'yield'

end

puts RoadSigns.sign #=> 'yield'

~~~~~~~~~~~~~~~~~~~~~

instance variables

an instance variable doesn't change the super classes or subclasses, it just changes the instance of the class

class RoadSigns

class << self; attr_accessor :sign end

@sign = 'stop'

end

puts Roadsigns.sign #=> 'stop'

---------------------------------------

class TheseSigns < RoadSigns

@sign = 'yield'

end

puts RoadSigns.sign #=> 'stop'

puts TheseSigns.sign #=> 'yield'

----------------------------------------

[appacademyview]

Magnetism and Endurance - Put Your Head Down

This place already has a sort of magnetic draw about it. I don't know what it is, if it's the sunny Soma location, the funny 1980's style ice-cube window blocks, the incredible bunch of people or the long long hours of brilliant, mind-bending, unending coding. Whatever it is, this morning I woke up and just had to get back there.

Ned and Kush started off with a lecture on the basics of object-orientation in programming, sparking certain tangental existential contemplations on "what do you mean by a real thing?" in response to a simplified explanation of, essentially, "what to make a class for." I mention this as a nice follow-up to something we realized yesterday: based on the function of ".split("")," we see that "between every thing there is nothing." We get a little too deep sometimes. So we talked about instance variables versus class variables and how to scope them appropriately for specific problems, and then got right back to work. Today involved a particular challenge, as the objective was to keep pairing with people who were at roughly the same place as you in the exercises, and get through as many as possible. Well I kept getting paired with people who had just started the same problem that I had just done, incidentally a particularly time-intensive one, and ended up pretty much doing it three times and making no progress on the other problems. So I'll be going in early tomorrow. The plus side is, by the third time around, being paired with someone who had not yet done any of it, I had the luxury of explaining to her how everything worked while she did the typing and asked the questions, which helped solidify it all in my own head. At any rate, we plowed through the code and stayed on it non-stop for most of the day and evening, except for one break where a few of us went down to a cafe to chill out for a few minutes around dinner time. The only downside of that was that I ordered a chai which was so spicy that it gave me the hiccups so bad that no amount of breath-holding would abolish them. One mate proposed that going back to the App Academy building is what finally cured them, and I'm afraid that if he is right, I'll be making some trips in at strange hours.