title: returning zero when converting string to integer in php
body: <p>when I want to convert a numeric string variable into integer in php, the return value is zero. I used all ways to convert it! such as:(int), (integer), intval(), settype(), eval(), etc. all of them return zero! </p>
  
  <p><code>var_dump($myVariable)</code> prints the following:</p>
  
  <pre><code>string(4) "۲۹"
  </code></pre>