title: preg_match find multiple partial appearances of a word in a string
body: <p>Any regex gurus around here? its driving me crazy.</p>
  
  <p>Say I have this string:
  "bookstore books Booking" </p>
  
  <p>I want to count the number "books" appears in this and return the number.</p>
  
  <p>Currently I have this which is not working:</p>
  
  <pre><code>$string = "bookstore books Booking";            
  if (preg_match_all('/\b[A-Z]+books\b/', $string, $matches)) {
    echo count($matches[0]) . " matches found";
  } else {
    echo "match NOT found";
  }
  </code></pre>
  
  <p>On top of this the "books" inside the preg_match_all should become a $var</p>
  
  <p>Anyone an idea how to count correctly?</p>