$IDCard = new IDCard();
var_dump($IDCard::isCard($_GET['card']));

/**
* 身份证处理类
*/
class IDCard {

//检证身份证是否正确
public static function isCard($card) {
$card = self::to18Card($card);
if (strlen($card) != 18) {
return false;
}

$cardBase = substr($card, 0, 17);

return (self::getVerifyNum($cardBase) == strtoupper(substr($card, 17, 1)));
}


//格式化15位身份证号码为18位
public static function to18Card($card) {
$card = trim($card);

if (strlen($card) == 18) {
return $card;
}

if (strlen($card) != 15) {
return false;
}

// 如果身份证顺序码是996 997 998 999，这些是为百岁以上老人的特殊编码
if (array_search(substr($card, 12, 3), array('996', '997', '998', '999')) !== false) {
$card = substr($card, 0, 6) . '18' . substr($card, 6, 9);
} else {
$card = substr($card, 0, 6) . '19' . substr($card, 6, 9);
}
$card = $card . self::getVerifyNum($card);
return $card;
}

// 计算身份证校验码，根据国家标准gb 11643-1999
private static function getVerifyNum($cardBase) {
if (strlen($cardBase) != 17) {
return false;
}
// 加权因子
$factor = array(7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2);

// 校验码对应值
$verify_number_list = array('1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2');

$checksum = 0;
for ($i = 0; $i < strlen($cardBase); $i++) {
$checksum += substr($cardBase, $i, 1) * $factor[$i];
}

$mod = $checksum % 11;
$verify_number = $verify_number_list[$mod];

return $verify_number;
}
}