title: Find first occurence numerical position in a string by php
body: <p>May I ask how to find a first occurrence numerical position in a string with PHP?
  For example, if <code>"abc2.mp3"</code> is a string, return a value of <code>3</code> since position of the first occurrence number <code>"2"</code> in <code>"abc2.mp3"</code> is <code>3</code> (the first position is <code>0</code>).</p>
  
  <p>I used <code>strpos()</code> function in PHP, it only returns whether the string is number or not, i.e. <code>TRUE</code> or <code>FALSE</code>.</p>
  
  <p>Thanks for your reply.</p>