undefined method `>' for [1000, []]:Array (NoMethodError)

Question

am trying to read the files of months for a year. In files there are some empty values. am trying to compare value of array (which i read from file) with default value but i keep getting the following error:

undefined method `>' for [1000, []]:Array (NoMethodError)

i checked the class of value which am getting from file it's integer but why then it's showing this error

def monthly_temperature(file_data)

  highest_temp  =  max_humdity = 0
  lowest_temp = 100 , info = []
  array = file_data.map { |string| string.split(',') }

  array.each_with_index do |days, ind|
   array[ind].shift()  #removing every first index

    if highest_temp < array[ind].first.to_i
      highest_temp = array[ind].first.to_i
    end

    a = array[ind].fetch(2).to_i
    #puts a.class

    if lowest_temp > a
      lowest_temp = a
    end
  end
end

Answer 1

Your javascript-like assignment:

lowest_temp = 100 , info = []

is equivalent to

lowest_temp = [100, info = []]

resulting lowest_temp holding an array. Correct parallel assignment is done like this:

lowest_temp, info = 100, []

Generally it should be only used when destructuring an array or when assigned values have a similar meaning (and assigning them together makes code easier to understand). In all the other cases, regular assignment is preferable for readability:

lowest_temp = 100
info = []