title: preg_match_all vs. explode
body: <p>why don't the following two php-codes return the same?</p>
  
  <p>Code 1:</p>
  
  <pre><code>$words = "music band sound";
  preg_match_all("/\w+/", strtoupper($words), $matches);
  $words = $matches[0];
  </code></pre>
  
  <p>and Code 2:</p>
  
  <pre><code>$words = "music band sound";
  $woerter  = strtoupper($words);
  $teile = explode(" ", $woerter);
  $words = $teile[0];
  </code></pre>
  
  <p>Can you please help me?</p>
  
  <p>Thank you!</p>