Multidimesional Array - `initialize': wrong number of arguments (1 for 0)

Question

I'm still new in Ruby on Rails. Today I'm trying to write some codes which can run the the following:

image = Image.new([
  [0, 0, 0, 0],
  [0, 1, 0, 0],
  [0, 0, 0, 1],
  [0, 0, 0, 0]
])

image.output_image

And I'm having trouble setup the initialize. My codes is as below, can someone help me? Thanks a lot

class Subary
    attr_accessor :num1, :num2, :num3, :num4

    def initialize (num1, num2, num3, num4)
        self.num1 = num1
        self.num2 = num2
        self.num3 = num3
        self.num4 = num4
    end

    def output_subary
        puts "#{num1}#{num2}#{num3}#{num4}"
    end

end

# subary = Subary.new(0,0,0,0)
# puts subary.output_subary

class Image
    def initialize 
        @subarys = []
        @subarys << Subary.new(:num1, :num2, :num3, :num4)
        @subarys << Subary.new(:num1, :num2, :num3, :num4)
        @subarys << Subary.new(:num1, :num2, :num3, :num4)
        @subarys << Subary.new(:num1, :num2, :num3, :num4)
    end

    def output_image
        @subarys.each do |list|
            list.output_subary
        end
    end
end

image = Image.new([
  [0, 0, 0, 0],
  [0, 1, 0, 0],
  [0, 0, 0, 1],
  [0, 0, 0, 0]
])
image.output_image

Answer 1

`initialize': wrong number of arguments (1 for 0)

This error means that, initialize method does not take any argument (0), but you passed one argument to it. Change the initialize method's definition in your Image class. Then, it should work.

class Subary
    attr_accessor :num1, :num2, :num3, :num4

    def initialize(sub_array)
        self.num1 = sub_array[0]
        self.num2 = sub_array[1]
        self.num3 = sub_array[2]
        self.num4 = sub_array[3]
    end

    def output_subary
        puts "#{num1}#{num2}#{num3}#{num4}"
    end
end

# subary = Subary.new(0,0,0,0)
# puts subary.output_subary

class Image
    def initialize(array_of_arrays)
        @subarys = []
        @subarys << Subary.new(array_of_arrays[0])
        @subarys << Subary.new(array_of_arrays[1])
        @subarys << Subary.new(array_of_arrays[2])
        @subarys << Subary.new(array_of_arrays[3])
    end

    def output_image
        @subarys.each do |list|
            list.output_subary
        end
    end
end

image = Image.new([
  [0, 0, 0, 0],
  [0, 1, 0, 0],
  [0, 0, 0, 1],
  [0, 0, 0, 0]
])
image.output_image
# => 0000
# => 0100
# => 0001
# => 0000