Function to Mask Numbers in PHP

Here is function to mask numbers

//////Code

arguments
$phonenumber : number to mask
$trim = number of digit to show
$maskCharacter = character to be displayed on masked digits

function maskNumber($phonenumber, $trim, $maskCharacter)
{
$str="";
$suffixNumber = substr($phonenumber, strlen($phonenumber)-$trim,$trim);
$prefixNumber = substr($phonenumber, 0, -$trim);

for ($x = 0; $x < strlen($prefixNumber); $x++):
    $str.= ( is_numeric($prefixNumber[$x]) )? str_replace($prefixNumber[$x], $maskCharacter, $prefixNumber[$x]) : $prefixNumber[$x];
endfor;

return  $str.$suffixNumber;    
}


HOW TO USE

Suppose you have large database of Mobile number of any other database which has to partially shown on the site or documents.then you can mask the number or string to protect your data

Example

IF I have an array for which i need to show only last four digits

$telarray = array('7383204940','7383323653','7878389652','8000306647','8000658282');

I would call it as

for($i=0;$i<count($telarray);$i++){
echo $masked = maskNumber($telarray[$i],4,'X');
echo '<br />';
}

OUTPUT would be

XXXXXX4940
XXXXXX3653
XXXXXX9652
XXXXXX6647
XXXXXX8282

Thanks

Cheers