<?php
// $mysqli is already declared as a working database connection by this sandbox
// $value may be a string or a flat array
function mask($value)
{
return preg_replace('/^.{0,3}\K.*/', '***', $value);
}
$result = $mysqli->query("SELECT * FROM my_table");
foreach ($result as $row) {
printf("%s %s\n", mask($row['first_name']), mask($row['last_name']));
}