Variables de Clase en Ruby
Una variable de clase es compartida entre todos los objectos de una clase.
Los nombres de variables de clase comienzan con dos arrobas (ejemplo: @@contador).
Las variables de clase deben ser inicializadas antes de ser utilizadas.
class Vehicle
def initialize(number_wheels,colour)
@number_wheels = number_wheels
@colour = colour
end
def to_s
"Vehicle:\tNumber Wheels:#{@number_wheels}\tColour:#{@colour}"
end
end
class Car < Vehicle
@@number_of_cars = 0
def initialize(number_wheels, colour, number_doors)
super(number_wheels, colour)
@number_doors = number_doors
@@number_of_cars += 1
end
def to_s
super + "\tNumber Doors:#{@number_doors}\tTotal Number of Car Actually:#{@@number_of_cars}"
end
end
carExample = Car.new(4,"red",5)
puts carExample.to_s
# Vehicle: Number Wheels:4 Colour:red Number Doors:5 Total Number of Car Actually:1
carExample2 = Car.new(4,"grey",5)
puts carExample2.to_s
# Vehicle: Number Wheels:4 Colour:grey Number Doors:5 Total Number of Car Actually:2
puts carExample.to_s
#Vehicle: Number Wheels:4 Colour:red Number Doors:5 Total Number of Car Actually:2