Credit-Card-Identification-and-Validation-Class--The-creditcard-class


            provides methods for cleaning, validating and identifying the type of credit card numbers
class credit_card 
{ 
 function clean_no ($cc_no) 
 { 
 // Remove non-numeric characters from $cc_no 
 return ereg_replace ('[^0-9]+', '', $cc_no); 
 } 
 function identify ($cc_no) 
 { 
 $cc_no = credit_card::clean_no ($cc_no); 
 // Get card type based on prefix and length of card number 
 if (ereg ('^4(.{12}|.{15})$', $cc_no)) 
 return 'Visa'; 
 if (ereg ('^5[1-5].{14}$', $cc_no)) 
 return 'Mastercard'; 
 if (ereg ('^3[47].{13}$', $cc_no)) 
 return 'American Express'; 
 if (ereg ('^3(0[0-5].{11}|[68].{12})$', $cc_no)) 
 return 'Diners Club/Carte Blanche'; 
 if (ereg ('^6011.{12}$', $cc_no)) 
 return 'Discover Card'; 
 if (ereg ('^(3.{15}|(2131|1800).{11})$', $cc_no)) 
 return 'JCB'; 
 if (ereg ('^2(014|149).{11})$', $cc_no)) 
 return 'enRoute'; 
 return 'unknown'; 
 } 
 function validate ($cc_no) 
 { 
 // Reverse and clean the number 
 $cc_no = strrev (credit_card::clean_no ($cc_no)); 
 // VALIDATION ALGORITHM 
 // Loop through the number one digit at a time 
 // Double the value of every second digit (starting from the right) 
 // Concatenate the new values with the unaffected digits 
 for ($ndx = 0; $ndx < strlen ($cc_no); ++$ndx) 
 $digits .= ($ndx % 2) ? $cc_no[$ndx] * 2 : $cc_no[$ndx]; 
 // Add all of the single digits together 
 for ($ndx = 0; $ndx < strlen ($digits); ++$ndx) 
 $sum += $digits[$ndx]; 
 // Valid card numbers will be transformed into a multiple of 10 
 return ($sum % 10) ? FALSE : TRUE; 
 } 
 function check ($cc_no) 
 { 
 $valid = credit_card::validate ($cc_no); 
 $type = credit_card::identify ($cc_no); 
 return array ($valid, $type, 'valid' => $valid, 'type' => $type); 
 } 
} 
?>
Algorithms Php
