title: mb_strpos vs strpos, what's the difference?
body: <p>Yes: I know. We should use mb_* function when we're working with multibyte char. But when we're using strpos?
  Let's take a look this code (saved in utf-8)</p>
  
  <pre><code>var_dump(strpos("My symbol utf-8 is the €.", "\xE2\x82\xAC")); // int(23)
  </code></pre>
  
  <p>There is a difference of using mb_strpos? Does't makes this work the same jobs? After all, does't <em>strpos</em> seek <strong>a string</strong> (multiple byte)?  Is there a reason to use instead strpos?</p>