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static and dynamic member variables and methods
More Classes and Objects example from a Well House Consultants training course
More on More Classes and Objects [link]
Source code: cmquick Module: R108
=begin Only one variable @@count exists in the class - it's known as a static of class variable. But two variables exist called @count - one for each class member. So they're known as object or dynamic variables. The getcount method is a dynamic or object method and can use both object and class variables. But the allcount method is a class or static method and can only refer to class or static variables. =end class Thing @@count = 0 def initialize(v) @@count += 1 @count = v end def getcount return [@count,@@count] end def self.allcount return [@@count] end end this = Thing.new(5) p this.getcount p Thing::allcount that = Thing.new(9) p this.getcount p that.getcount p Thing::allcount # Note :: and . mean the same thing - but it's accepted common # practise to use :: on a static class member call, and . on a # dynamic object call. # If I want to call a static method on a class member (i.e. to # ask something in general about the class of which an object is # a member, I can do so by using the .class method on the object # then calling the static method on the class: p this.class.allcount Learn about this subject
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