title: Explode a string on upper case characters?
body: <p>Ho can i explode <code>$param</code> string into <code>$chunks</code> pieces based on upper-case characters?</p>
  
  <pre><code>$string = 'setIfUnmodifiedSince';
  $method = substr($string, 0, 3);
  $param  = substr($string, 3);
  
  // Split $param and implode with '-' separator
  $chunks = splitAtUpperCase($param); // Chunks are: 'If', 'Unmodified' and 'Since'
  $field  = implode('-', $chunks); // Get If-Unmodified-Since HTTP field name
  </code></pre>