Several ID card functions_PHP tutorial

​ I wrote several functions related to ID cards, which I personally feel are quite useful. Especially when conducting online questionnaires, it is very useful to verify the ID card in personal information. However, there are only a few applicants, so I might as well keep it in my blog. .
// Calculate ID card verification code according to national standard GB 11643-1999
function idcard_verify_number($idcard_base){
if (strlen($idcard_base) != 17){ return false; }
// Weighting factor
$factor = array(7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2);

// Corresponding value of check code
$verify_number_list = array('1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2');
$checksum = 0;
for ($i = 0; $i < strlen($idcard_base); $i++){
$checksum += substr($idcard_base, $i, 1) * $factor[$i];
}
$mod = $checksum % 11;
$verify_number = $verify_number_list[$mod];
Return $verify_number;
}
// Upgrade the 15-digit ID card to 18-digits
function idcard_15to18($idcard){
if (strlen($idcard) != 15){
       return false;
}else{
// If the ID card sequence code is 996 997 998 999, these are special codes for people over 100 years old
If (array_search(substr($idcard, 12, 3), array('996', '997', '998', '999')) !== false){
               $idcard = substr($idcard, 0, 6) . '18'. substr($idcard, 6, 9);
     }else{
               $idcard = substr($idcard, 0, 6) . '19'. substr($idcard, 6, 9);
}
}
$idcard = $idcard . idcard_verify_number($idcard);
Return $idcard;
}
// 18-digit ID card verification code validity check
function idcard_checksum18($idcard){
if (strlen($idcard) != 18){ return false; }
$idcard_base = substr($idcard, 0, 17);

http://www.bkjia.com/PHPjc/445576.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/445576.htmlTechArticleWritten several ID card functions, which I personally find quite useful, especially when conducting online surveys. It is very useful to verify the ID card in personal information, but there are very few people who respond, or...