Useful for a number of things including username and anything else you don’t want ANY special chars in, leaving only alphanumeric digits.
<?php $string = 'us$$er*&^nam@@e'; $string = cleanabc123($string); function cleanabc123($data) { $data = preg_replace("/[^a-zA-Z0-9\s]/", "", $data); return $data; } // This will be 'username' now echo $string; ?>
And if you wanted it to also remove whitespace, you could change the function by removing the \s whitespace character.
$data = preg_replace("/[^a-zA-Z0-9]/", "", $data);