title: delete all values from an array while keeping keys intact
body: <p>Do I really have to do this to reset an array?</p>
  <pre><code>foreach ($array as $i =&gt; $value) {
      unset($array[$i]);
  }
  </code></pre>
  <p>EDIT:</p>
  <p>This one makes more sense, as the previous one is equivalent to <code>$array=array();</code></p>
  <pre><code>foreach ($array as $i =&gt; $value) {
      $array[$i]=NULL;
  }
  </code></pre>