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 valid49927398717 is not valid1234567812345678 is not valid1234567812345670 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>";

输出结果如下

49927398716 is valid49927398717 is not valid1234567812345678 is not valid1234567812345670 is valid

希望本文所述对大家的php程序设计有所帮助。