Module: Luhn
- Defined in:
- lib/luhn.rb,
lib/luhn_ruby/version.rb
Defined Under Namespace
Classes: Error
Constant Summary collapse
- VERSION =
"0.1.0"
Class Method Summary collapse
Class Method Details
.valid?(number) ⇒ Boolean
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# File 'lib/luhn.rb', line 7 def self.valid?(number) sum = 0 number.reverse.chars.each_with_index do |ch, index| num = ch.to_i num *= 2 if index.odd? num -= 9 if num >= 10 sum += num end (sum % 10).zero? end |