title: php preg_split with special chars
body: <pre><code>$tags = preg_split('@ @', 'Hello World 1 2  3 45   54', NULL, PREG_SPLIT_NO_EMPTY);
  print_r($tags);
  $tags = preg_split('/ /', 'Hello World 1 2  3 45   54', NULL, PREG_SPLIT_NO_EMPTY);
  print_r($tags);
  
  $tags = preg_split('@/@', '1/2//3', NULL, PREG_SPLIT_NO_EMPTY);
  print_r($tags);
  $tags = preg_split('/\//', '1/2//3', NULL, PREG_SPLIT_NO_EMPTY);
  print_r($tags);
  </code></pre>
  
  <p>Why is the last one not working?, what is exactly the difference of @ with / for building php regex?</p>
  
  <p>thx for clarifications</p>