title: "range out of order in character class" in PHP regex?
body: <p>I am trying to get this work for a while but in vain.
  I want to create a php regex to check if a string has atleast one number and atleast one of the symbols amongst ( _-+=*&amp; )</p>
  
  <p>This is my regex</p>
  
  <pre><code> $result = preg_match('/^(?=.*\d)(?=.*[_-+=*&amp;]).{3,}$/',$pass);
  </code></pre>
  
  <p>I get the following error 
         Warning: preg_match() [function.preg-match]: Compilation failed: range out of order in character          class       at offset 17 in myfile.php on line 8</p>
  
  <p>any help ?</p>