class Bookland::EAN
Constants
- WEIGHTS
Public Class Methods
calculate_checksum_digit(digits)
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# File lib/bookland/ean.rb, line 5 def self.calculate_checksum_digit(digits) sum = digits.map(&:to_i).zip(WEIGHTS).reduce(0) { |a, (i, j)| a + i * j } ((10 - sum % 10) % 10).to_s end
Public Instance Methods
valid?()
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Calls superclass method
# File lib/bookland/ean.rb, line 10 def valid? digits.size == 13 && super end