Luhn test of credit card numbers: Difference between revisions

==={{header|Chipmunk Basic}}===

{{works with|Chipmunk Basic|3.6.4}}

<syntaxhighlight lang="qbasic">100 cls

110 rem Luhn test

120 dim card$(5)

130 card$(1) = "49927398716"

140 card$(2) = "49927398717"

150 card$(3) = "1234567812345678"

160 card$(4) = "1234567812345670"

170 for test = 1 to 4

180 odd = true

190 sum = 0

200 for n = len(card$(test)) to 1 step -1

210 num = val(mid$(card$(test),n,1))

220 if odd then

230 sum = sum+num

240 odd = false

250 else

260 num = num*2

270 if num <= 9 then

280 sum = sum+num

290 else

300 sum = sum+val(left$(str$(num),1))+val(right$(str$(num),1))

310 endif

320 odd = true

330 endif

340 next

350 if sum mod 10 = 0 then

360 print card$(test),"True"

370 else

380 print card$(test),"False"

390 endif

400 next test</syntaxhighlight>