Solved

need help with a script that should replace last x digits of a number with "x", it does all but the last x

Posted on 2008-06-25
8
211 Views
Last Modified: 2011-10-19
Hi

I have the function attached that takes a string (card number) and should turn the last x digits into "x" to obscure the number. It almost works but turns the last x into "x", it should be everything BUT the last x.

Example: 1234 5678 1234 5678
is becoming 1234 5678 12xx xxxx
it should be xxxx xx34 1234 5678
/**
	* returns part of the parameter
	*	
	* @param string $cardNumber
	* @return	string $safeNumber
	* @access	private
	*/
	private function safeNumber($cardNumber) {	
		$safeNumber = "";
		$char = "x";
		$numToHide = 6;		
		$cardNumber = substr($cardNumber, 0, strlen($cardNumber) - $numToHide);		
		for ($i = 0; $i < $numToHide; $i++) {
				$cardNumber .= $char;
		}			
		for ($startPos = 0; $startPos <= strlen($cardNumber); $startPos+=4)	{
			$safeNumber .= substr($cardNumber, $startPos, 4) . " ";
		}
		return $safeNumber;
	}

Open in new window

0
Comment
Question by:Neil Thompson
  • 2
  • 2
  • 2
  • +2
8 Comments
 
LVL 6

Accepted Solution

by:
Iced-evil earned 500 total points
ID: 21865202
modify this :

$cardNumber = substr($cardNumber, 0, strlen($cardNumber) - $numToHide);            
            for ($i = 0; $i < $numToHide; $i++) {
                        $cardNumber .= $char;
            }                  


into


$cardNumber = substr($cardNumber, $numToHide, strlen($cardNumber));            
            for ($i = 0; $i < $numToHide; $i++) {
                        $cardNumber = $char . $cardNumber;
            }                  
0
 
LVL 9

Expert Comment

by:Rob Siklos
ID: 21865223
This should work:
<?
private function safeNumber($cardNumber) {      
        $safeNumber = "";
        $char = "x";
        $numToHide = 6;         
 
        $numDone = 0;
        
        for ($i = 0; $i < $strlen($cardNumber); $i++) {
            $currChar = substr($cardNumber, $i, 1);
            if (($currChar == ' ') || $numDone > $numToHide) {
                $safeNumber .= $currChar;
            }
            else {
                $safeNumber .= $char;
            }
        }
 
        return $safeNumber;
}

Open in new window

0
 
LVL 9

Expert Comment

by:Rob Siklos
ID: 21865226
shoot - ignore the last one - use this:
<?
private function safeNumber($cardNumber) {      
        $safeNumber = "";
        $char = "x";
        $numToHide = 6;         
 
        $numDone = 0;
        
        for ($i = 0; $i < $strlen($cardNumber); $i++) {
            $currChar = substr($cardNumber, $i, 1);
            if (($currChar == ' ') || $numDone > $numToHide) {
                $safeNumber .= $currChar;
            }
            else {
                $safeNumber .= $char;
                $numDone++;
            }
        }
 
        return $safeNumber;
}

Open in new window

0
Networking for the Cloud Era

Join Microsoft and Riverbed for a discussion and demonstration of enhancements to SteelConnect:
-One-click orchestration and cloud connectivity in Azure environments
-Tight integration of SD-WAN and WAN optimization capabilities
-Scalability and resiliency equal to a data center

 
LVL 3

Author Closing Comment

by:Neil Thompson
ID: 31470542
Thanks all, this worked!
0
 
LVL 7

Expert Comment

by:dineesh
ID: 21865303
HI Can i recommend a simpler way,

i dont know javascript so have sent a sample in excel, you have to try the same logic in js

=REPT(B3,B2)&RIGHT(B1,LEN(B1)-B2)
safecard.xls
0
 
LVL 2

Expert Comment

by:HengTime
ID: 21865357
i would replace this:

  $cardNumber = substr($cardNumber, 0, strlen($cardNumber) - $numToHide);        
                for ($i = 0; $i < $numToHide; $i++) {
                                $cardNumber .= $char;
                }                      
                for ($startPos = 0; $startPos <= strlen($cardNumber); $startPos+=4)     {
                        $safeNumber .= substr($cardNumber, $startPos, 4) . " ";
                }

with this

$cardNumber = substr($cardNumber, $numToHide );  
$safeNumber = str_repeat("x",$numToHide).$cardNumber;
0
 
LVL 3

Author Comment

by:Neil Thompson
ID: 21865421
Many thanks, all useful comments for me to take worward as I progress and look back over the code to clean it.
0
 
LVL 7

Expert Comment

by:dineesh
ID: 21865521
oops sorry,
i missed the fact that it was php code,  i dont know that either...
0

Featured Post

Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Deprecated and Headed for the Dustbin By now, you have probably heard that some PHP features, while convenient, can also cause PHP security problems.  This article discusses one of those, called register_globals.  It is a thing you do not want.  …
This article discusses how to create an extensible mechanism for linked drop downs.
The viewer will learn how to look for a specific file type in a local or remote server directory using PHP.
This tutorial will teach you the core code needed to finalize the addition of a watermark to your image. The viewer will use a small PHP class to learn and create a watermark.

808 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question