Replace username part in email addresses into asterisks - php

Question

How can I convert username in email addresses into asterisks. The first and last letter in the username stay as it is and rest replaced with (*).
Example:
mhyunf#gmail.com
into
m****f#gmail.com

Answer 1

You can do it using look arounds.
/(?!^).(?=[^#]+#)/
(?!^) Negative look behind. Checks if the character is not preceded by start of string. This ensures that the first character is not selected.
. Matches a single character.
(?=[^#]+#) Positive look ahead. Ensures that the single character matched is followed by anything other than # ( ensured by [^#] ) and then a #
Regex Demo
Example
preg_replace("/(?!^).(?=[^#]+#)/", "*", "mhyunf#gmail.com")
=> m****f#gmail.com

Answer 2

Or alternatively if you don't wanna use regex you can do something like this
function filterEmail($email) {
$emailSplit = explode('#', $email);
$email = $emailSplit[0];
$len = strlen($email)-1;
for($i = 1; $i < $len; $i++) {
$email[$i] = '*';
}
return $email . '#' . $emailSplit[1];
}

Answer 3

function hideEmail($email, $domain_ = false){
$seg = explode('#', $email);
$user = '';
$domain = '';
if (strlen($seg[0]) > 3) {
$sub_seg = str_split($seg[0]);
$user .= $sub_seg[0].$sub_seg[1];
for ($i=2; $i < count($sub_seg)-1; $i++) {
if ($sub_seg[$i] == '.') {
$user .= '.';
}else if($sub_seg[$i] == '_'){
$user .= '_';
}else{
$user .= '*';
}
}
$user .= $sub_seg[count($sub_seg)-1];
}else{
$sub_seg = str_split($seg[0]);
$user .= $sub_seg[0];
for ($i=1; $i < count($sub_seg); $i++) {
$user .= ($sub_seg[$i] == '.') ? '.' : '*';
}
}
$sub_seg2 = str_split($seg[1]);
$domain .= $sub_seg2[0];
for ($i=1; $i < count($sub_seg2)-2; $i++) {
$domain .= ($sub_seg2[$i] == '.') ? '.' : '*';
}
$domain .= $sub_seg2[count($sub_seg2)-2].$sub_seg2[count($sub_seg2)-1];
return ($domain_ == false) ? $user.'#'.$seg[1] : $user.'#'.$domain ;
}