Php > Miscellaneous

Credit card Validation

Credit card Validation

This script is object orianted but I included a simple wrapper funtion. 
It makes it easy by just entering the card number and returning a boolean true or false; 

boolean IsCardValid(int); 
boolean IsCardValid(string); 

<?php 

class CCValidation{ 
    // static variables 
   var $INVALID    = -1; 
   var $VISA       = 1; 
   var $MASTERCARD = 2; 
   var $AMEX       = 3; 
   var $CARD_NAMES = array("Visa","Mastercard","American Express"); 

    // data members 
   var $CardNumber = ""; 

   function CCValidation($set_num){ 
      $this->CardNumber = $set_num; 

   } 
   function setCardNumber($set_num){ 
      $this->CardNumber = $set_num; 
   } 
   function CheckCardID(){ 
      $valid = $INVALID; 

      $digits1 = substr($this->CardNumber,0,1); 
      $digits2 = substr($this->CardNumber,0,2); 
      $digits4 = substr($this->CardNumber,0,4); 
        
      if($digit1 == 4){ 
         if(strlen($this->CardNumber) == 13 || strlen($this->CardNumber) == 16){ 
             $valid = $VISA; 
         } 
      }else if($digit2 >= 51 && $digit2 <= 55){ 
         if(strlen($this->CardNumber) == 16){ 
            $valid = $MASTERCARD; 
         } 
      }else if($digit2 == 34 || $digit2 == 37){ 
         if(strlen($this->CardNumber) == 15){ 
            $valid = $AMEX; 
         } 
      } 
      return $valid; 
   } 
   function CheckCardNumber(){ 
      $cardTemp = $this->CardNumber; 
      $checkSum = 0; 
        
      for($i = (strlen($cardTemp) -1);$i >= 0; $i -= 2){ 
          $j = 0; 
          if(i > 0){ 
            $j = substr($cardTemp,$i-1,$i) * 2; 
            if($j > 9){ 
               $s = $j; 
               $j = substr($s,0,1) + substr($s,1); 
            } 
            $checkSum += substr($s,0,1) + $j; 
          }else{ 
            $checkSum += substr($cardTemp,0,1); 
          } 
      } 
      return (($checkSum % 10) == 0); 
   } 
   function CheckCard(){ 
      if($this->CheckCardID() != -1){ 
         return $this->CheckCardNumber(); 
      } 
      return false; 
   } 
} 
function IsCardValid($card_num){ 
   $card = new CCValidation($card_num); 
   return $card->CheckCard(); 
} 
?>