PHP实现通过Luhn算法校验信用卡卡号是否有效
本文实例讲述了PHP实现通过Luhn算法校验信用卡卡号是否有效的方法。分享给大家供大家参考。具体实现方法如下：
$numbers = "49927398716 49927398717 1234567812345678 1234567812345670";
foreach (split(' ', $numbers) as $n)
echo "$n is ", luhnTest($n) ? 'valid' : 'not valid', '</br>';
function luhnTest($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 $sum % 10 == 0;
}
运行结果
49927398716 is valid 49927398717 is not valid 1234567812345678 is not valid 1234567812345670 is valid
下面是一个更为简洁的代码：
复制代码 代码如下:
function luhn_test($num) {
$str = '';
foreach( array_reverse( str_split( $num ) ) as $i => $c ) $str .= ($i % 2 ? $c * 2 : $c );
return array_sum( str_split($str) ) % 10 == 0;
}
foreach (array('49927398716','49927398717','1234567812345678','1234567812345670') as $n)
echo "$n is ", luhn_test($n) ? 'valid' : 'not valid', "</br>\n";
$str = '';
foreach( array_reverse( str_split( $num ) ) as $i => $c ) $str .= ($i % 2 ? $c * 2 : $c );
return array_sum( str_split($str) ) % 10 == 0;
}
foreach (array('49927398716','49927398717','1234567812345678','1234567812345670') as $n)
echo "$n is ", luhn_test($n) ? 'valid' : 'not valid', "</br>\n";
输出结果如下
49927398716 is valid 49927398717 is not valid 1234567812345678 is not valid 1234567812345670 is valid
希望本文所述对大家的php程序设计有所帮助。