module LuhnAlgorithm
Constants
- NUMBER_ONLY
- VERSION
Public Class Methods
valid?(value)
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# File lib/luhn_algorithm.rb, line 7 def self.valid?(value) value = value.to_s.reverse return false unless value.match(NUMBER_ONLY) arr = value.chars.map(&:to_i) (1...(arr.length)).step(2) do |index| arr[index] = (arr[index] * 2).divmod(10).sum end (arr.sum % 10).zero? end