Question

Specifically, it should be 6 or more alphanumerics (0-9 + a-z).

The second character is a letter.

The third character is an odd number.

Any help?

Answer 1

An example regex that matches this for ASCII is

^[0-9A-Za-z][A-Za-z][13579][0-9A-Za-z]{3,}$

PHP code

<?php
$test = '0A1000';
if (preg_match('/^[0-9A-Za-z][A-Za-z][13579][0-9A-Za-z]{3,}$/', $test)) {
    // Do some stuff
    echo "matched";
}