Ytukyg

I am struggling to understand how I can access an array with a hash key. In my code, I create a hash with keys and values. Now, I want to set the values in a Car class. Whenever I try to instantiate the Car, the argument expects Integer and not a String.

I am getting the following error: TypeError (no implicit conversion of String into Integer)

Here is my code:

class Car_maker



 attr_accessor :car_maker



 def initialize(car_maker)

  @car_maker = car_maker

 end



end



class Car_model < Car_maker



attr_accessor :km, :type, :transmission, :stock, :drivetrain, :status, 

:fuel, :car_maker, :model, :year, :trim, :features

#total number of instances & array with car objects

@@totalCars = 0

@@catalogue = 



def initialize(km, type, transmission, stock, drivetrain, status, fuel, car_maker, model, year, trim, features)

    super(car_maker)

    @km = km

    @type = type

    @transmission = transmission

    @stock = stock

    @drivetrain = drivetrain

    @status = status

    @fuel = fuel

    @model = model

    @year = year

    @trim = trim

    @features = features

    @@totalCars += 1

end 



def self.convertListings2Catalogue(line)

    #Initialise arrays and use them to compare

    type = ["Sedan", "coupe", "hatchback", "station", "SUV"]

    transmission = ["auto", "manual", "steptronic"]

    drivetrain = ["FWD", "RWD", "AWD"]

    status = ["new", "used"]

    car_maker = ["honda", "toyota", "mercedes", "bmw", "lexus"]

    hash = Hash.new



    #In this part, we hash the set of features using regex

    copyOfLine = line

    regex = Regexp.new(/{(.*?)}/)

    match_array = copyOfLine.scan(regex)



    match_array.each do |line|

        hash["features"] = line

    end



    #Now, we split every comma and start matching fields

    newStr = line[0...line.index('{')] + line[line.index('}')+1...line.length]

    arrayOfElements = newStr.split(',')



    arrayOfElements.each do |value|

        if value.include?("km") and !value.include?("/")

            hash["km"] = value

        elsif type.include?(value)

            hash["type"] = value

        elsif transmission.include?(value.downcase)

            hash["transmission"] = value

        elsif value.include?("/") and value.include?("km")

            hash["fuel economy"] = value

        elsif drivetrain.include?(value)

            hash["drivetrain"] = value

        elsif status.include?(value.downcase)

            hash["status"] = value

        elsif /(?=.*[a-zA-Z])(?=.*[0-9])/.match(value) and !value.include?("km")

            hash["stock"] = value

        elsif car_maker.include?(value.downcase)

            hash["carmaker"] = value

        elsif /^d{4}$/.match(value)

            hash["year"] = value

        elsif value.length == 2

            hash["trim"] = value

        else

            if value.length > 2

                hash["model"] = value

            end

        end 

    end 

  end

 end



 textFile = File.open('cars.txt', 'r')

 textFile.each_line{|line|

   if line.length > 2

    result = Car_model.convertListings2Catalogue(line)

    puts "Hash: #{result}"



    carObj = Car_model.new(result["km"], result["type"], result["transmission"], result["stock"], result["drivetrain"],

    result["status"], result["fuel"], result["carmaker"], result["model"], result["year"], result["trim"], result["features"])

    #@@catalogue.push (carObj)

end

}

This line

result = Car_model.convertListings2Catalogue(line)

Doesn't return the hash object. It returns arrayOfElements since that's what the each method actually returns and the each method is the last method executed in the method (although there are hash assignments within it, it's only the last value that's returned unless you use an explicit return statement.

Just use the variable hash in the last line of the convertListing2Catalog method

        if value.length > 2

          hash["model"] = value

        end

      end 

    end 

    hash # < this is the last line of the method so it's the value that will be returned

  end

end

If you think about it, there were several variables created in the method. There's no reason to expect that the contents of any specific variable such as hash would be returned, and ruby methods by default return the last executed command.