Ruby透过Luhn算法验证信用卡卡号的有效性
Ruby通过Luhn算法验证信用卡卡号的有效性
运行结果如下
def luhn(code) s1 = s2 = 0 code.to_s.reverse.chars.each_slice(2) do |odd, even| s1 += odd.to_i double = even.to_i * 2 double -= 9 if double >= 10 s2 += double end (s1 + s2) % 10 == 0 end [49927398716, 49927398717, 1234567812345678, 1234567812345670].each do |n| p [n, luhn(n)] end
运行结果如下
[49927398716, true] [49927398717, false] [1234567812345678, false] [1234567812345670, true]