Extract Only numbrs from long string using Regex with PHP (Regular Expressions)

Here is a string -: RT4646R@TWBNSN3234FHFHFH893892389FHDJJD$

Now How will find all red marked numbers in an Array.Here is solution.

<?php

$string = 'RT4646R@TWBNSN3234FHFHFH893892389FHDJJD$';

$special_char = '\[#$%^&*()+=\-\[\]\';,.\/{}|":<>?~\\\\]';

preg_match_all('/\d+/', $string,$output);

echo '<pre>';

print_r($output[0]);

?>

Here is the output

Author - 

Sudhir K gupta | Lonawala