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credit card number verification 1
- Thread starter DeepBlerg
- Start date
something for you.
function checkCC($a){
$count=0;
for($i=strlen($a)-1; $i>=0;$i--){
$count+=(((strlen($a)-$i-1)%2)==0) ? $a[$i] : (floor($a[$i]*2/10)+($a[$i]*2%10));
}
return (($count%10)==0) ? true : false;
}
Anikin
Hugo Alexandre Dias
Web-Programmer
anikin_jedi@hotmail.com
function checkCC($a){
$count=0;
for($i=strlen($a)-1; $i>=0;$i--){
$count+=(((strlen($a)-$i-1)%2)==0) ? $a[$i] : (floor($a[$i]*2/10)+($a[$i]*2%10));
}
return (($count%10)==0) ? true : false;
}
Anikin
Hugo Alexandre Dias
Web-Programmer
anikin_jedi@hotmail.com
-
1
- #3
sleipnir214
Programmer
Anikin's code will check the luhn-10 checksum of a credit-card number presented. Use it.
I recommend you also perform other other checks, too, based on the type of card. For example, it is possible to input a supposed Visa number that passes luhn-10, but does not begin with a "4", as all Visa card numbers must.
Here's the guts of a switch statement I have used in my code before:
[tt]
$cc_good = FALSE;
switch ($cc_brand)
{
case "MasterCard" :
$cc_good = preg_match ("/^5[1-5]\d{14}$/", $cc_num);
break;
case "Visa" :
$cc_good = preg_match ("/^4\d{15}$|^4\d{12}$/", $cc_num);
break;
case "American Express" :
$cc_good = preg_match ("/^3[47]\d{13}$/", $cc_num);
break;
case "Discover" :
$cc_good = preg_match ("/^6011\d{12}$/", $cc_num);
break;
case "Diner's Club" :
$cc_good = preg_match ("/^30[0-5]\d{11}$|^3[68]\d{12}$/", $cc_num);
break;
case "Japan Credit Bank" :
$cc_good = preg_match ("/^3\d{15}$|^2131\d{11}$|1800\d{15}$/", $cc_num);
break;
default :
break;
}[/tt] ______________________________________________________________________
My God! It's full of stars!
______________________________________________________________________
I recommend you also perform other other checks, too, based on the type of card. For example, it is possible to input a supposed Visa number that passes luhn-10, but does not begin with a "4", as all Visa card numbers must.
Here's the guts of a switch statement I have used in my code before:
[tt]
$cc_good = FALSE;
switch ($cc_brand)
{
case "MasterCard" :
$cc_good = preg_match ("/^5[1-5]\d{14}$/", $cc_num);
break;
case "Visa" :
$cc_good = preg_match ("/^4\d{15}$|^4\d{12}$/", $cc_num);
break;
case "American Express" :
$cc_good = preg_match ("/^3[47]\d{13}$/", $cc_num);
break;
case "Discover" :
$cc_good = preg_match ("/^6011\d{12}$/", $cc_num);
break;
case "Diner's Club" :
$cc_good = preg_match ("/^30[0-5]\d{11}$|^3[68]\d{12}$/", $cc_num);
break;
case "Japan Credit Bank" :
$cc_good = preg_match ("/^3\d{15}$|^2131\d{11}$|1800\d{15}$/", $cc_num);
break;
default :
break;
}[/tt] ______________________________________________________________________
My God! It's full of stars!
______________________________________________________________________
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