Anonymous user
Luhn test of credit card numbers: Difference between revisions
→{{header|JavaScript}}
Line 3,099:
// returns false
luhn10('4111111111111112')
</lang>
Naive implementation
<lang javascript>const lunhCheck = (str) => {
const sumDigit = (c) => (c < 10) ? c :
sumDigit( Math.trunc(c / 10) + (c % 10));
return str.split('').reverse()
.map(Number)
.map((c, i) => i % 2 !== 0 ? sumDigit(c * 2) : c)
.reduce((acc,v) => acc + v) % 10 === 0;
};
lunhCheck('49927398716'); // returns true
lunhCheck('49927398717'); // returns false
lunhCheck('1234567812345678'); // returns false
lunhCheck('1234567812345670'); // returns true
</lang>
| |||