title: How to strip non-alphabetic, spaces and numeric characters from a string?
body: <p>How can I use php and regex to strip all <code>non-alphabetic</code>, <code>spaces</code> and all <code>numeric</code> from a string?</p>
  
  <p>I've tried this:</p>
  
  <pre><code>$input = "Hello - World 12";
  $output = preg_replace("/[^a-zA-Z0-9\s]/", "", $input);
  </code></pre>
  
  <p>Wanted output: <code>HelloWorld</code></p>