hide credit card number with Xs

[cmdr_bond]

I am making a secure payments website where people pay with their credit cards. If I have the cc number in a variable, how can I display it on the "confirm this information is accurate" page having Xs in place of all but the last 4 digits? (Eg: 1234567890123456 --> xxxxxxxxxxxx3456)

Thanks

[kpowning]

what about using:

http://us3.php.net/manual/en/function.preg-replace.php

[cmdr_bond]

Okay, I'm playing around with it and I think I got it to work:

$cc = "1234567890123456";
$cclength = strlen($cc);
$ccposshow = $cclength - 4;
$ccdisp = substr($cc, $ccposshow);
for ( $counter = 1; $counter <= $ccposshow; $counter += 1) {
$ccdisp = "x" . $ccdisp;
}
echo $ccdisp;

... do you think there's an easier way to do all of this?

[samudasu]

mike97gt at yahoo dot com
01-Dec-2005 03:04
Use str_pad to mask a credit card number.

<?
$ccnum = $_POST['CC_Number'];
$ccmask = str_pad(substr($ccnum, -4), strlen($ccnum), 'x', STR_PAD_LEFT);
?>

Works great for storing last 4 digits of credit card number in a database.