Luhn test of credit card numbers: Difference between revisions

==={{header|uBasic/4tH}}===

{{Trans|C}}

<syntaxhighlight lang="qbasic">Print " 49927398716", Show (Iif(FUNC(_Luhn ("49927398716")), "ok", "fail"))

Print " 49927398717", Show (Iif(FUNC(_Luhn ("49927398717")), "ok", "fail"))

Print "1234567812345678", Show (Iif(FUNC(_Luhn ("1234567812345678")), "ok", "fail"))

Print "1234567812345670", Show (Iif(FUNC(_Luhn ("1234567812345670")), "ok", "fail"))

End

_Luhn

Param (1)

Local (4)

c@ = 1 : d@ = 0

For b@ = Len(a@)-1 To 0 Step -1

e@ = Peek(a@, b@) - Ord("0")

d@ = d@ + Iif (c@, e@, e@+e@-9*(e@>4))

c@ = c@ = 0

Next

Return ((d@ % 10) = 0)

</syntaxhighlight>

{{Out}}

<pre> 49927398716 ok

49927398717 fail

1234567812345678 fail

1234567812345670 ok

0 OK, 0:333</pre>