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Luhn test of credit card numbers: Difference between revisions

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Luhn test of credit card numbers (view source)

Revision as of 22:33, 21 April 2021

3 bytes added ,  3 years ago
m
→‎{{header|Batch File}}: added good practice
m (→‎{{header|Batch File}}: added good practice)
Line 1,201:
<lang dos>@echo off
setlocal enabledelayedexpansion
)▼
 
call :luhn 49927398716
call :luhn 49927398717
Line 1,207:
call :luhn 1234567812345670
exit /b 0
 
:luhn
set "input=%1"
set "cnt=0"
set "s1=0&set s2=0"
set "s2=0"
:digit_loop
set /a "cnt-=1"
set /a "isOdd=^(-%cnt%^)%%2"
 
if !isodd! equ 1 (
set /a "s1+=!input:~%cnt%,1!"
) else (▼
set /a "twice=!input:~%cnt%,1!*2"
if !twice! geq 10 (▼
set /a "s2+=!twice:~0,1!+!twice:~1,1!"▼
) else (
set /a twice"s2+=!input:~%cnt%,1twice!*2"
▲ if !twice! geq 10 (
▲ set /a s2+=!twice:~0,1!+!twice:~1,1!
▲ ) else (
set /a s2+=!twice!
)
)
)
if "!input:~%cnt%!"=="!input!" (
set /a "sum=^(!s1!+!s2!^)%%10"
if !sum! equ 0 (echo !input! is valid.) else (echo !input! is not valid.)
goto :EOF
▲ )
)
goto digit_loop</lang>
{{Out}}
<pre>>luhn.bat
Simple9371
535

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