title: Use preg_split for all special characters
body: <p>I want to split a String everytime a special character is found.</p>
  
  <p>I did this :</p>
  
  <pre><code>preg_split("[\\W]", $str);
  </code></pre>
  
  <p>But this will still allow underscore (and maybe more?) </p>
  
  <p>Is it possible to just say allow a-z A-Z and digits and split on anything that is not one of these?</p>