# create instance variables by prefixing a variable name with @.
# create class variables by prefixing a variable's name with @@.
# A class variable is shared by all instances of a class
# Only one copy of a class variable exists for a given class.
# You have to initialize (declare a value for) a class variable before you use it.
class Animal
@@number_animals = 0
def initialize(color)
@color = color
@@number_animals += 1
end
def get_color
return @color
end
def get_number_animals
return @@number_animals
end
end
dog = Animal.new("brown")
cat = Animal.new("striped")
squirrel = Animal.new("gray")
puts "Number of animals is " + squirrel.get_number_animals.to_s
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