PHP实现通过Luhn算法校验信用卡卡号是否有效_PHP教程

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

$numbers = "49927398716 49927398717 1234567812345678 1234567812345670";

foreach (split(' ', $numbers) as $n)

echo "$n is ", luhnTest($n) ? 'valid' : 'not valid', '
';

function luhnTest($num) {

$len = strlen($num);

for ($i = $len-1; $i >= 0; $i--) {

$ord = ord($num[$i]);

if (($len - 1) & $i) {

$sum += $ord;

} else {

$sum += $ord / 5 + (2 * $ord) % 10;

}

}

return $sum % 10 == 0;

}

1

2

3

4

49927398716 is valid

49927398717 is not valid

1234567812345678 is not valid

1234567812345670 is valid

1

2

3

4

49927398716 is valid

49927398717 is not valid

1234567812345678 is not valid

1234567812345670 is valid