credit_check

HW Solution

card_number = "4929735477250543"

separate_nums = card_number.chars.map(&:to_i).reverse
initial_collection = separate_nums.each_with_index.map do |digit,index|
  if index.odd?
    digit *= 2
  else
    digit
  end
end


total = initial_collection.map do |num|
  if num > 9
    num.to_s.split("").map {|digit| digit.to_i}.reduce(:+)
  else
    num
  end
end

if total.reduce(:+) % 10 == 0
  "The number is valid!"
else
  "The number is invalid"
end