title: PHP set value to null when return
body: <p>This question probably weird but I can't answer anywhere. Do I need to set value to <code>null</code> when returning (save memory)?</p>
  
  <pre><code>      ...
        $output =  $DB -&gt;query("SELECT * FROM TABLE WHERE ...", $param);
  
        if (empty($output))
        {
            throw new Exception('Error');
        }
        else
        {
            return $output;
            $output = null;
        }
  </code></pre>
  
  <p>Or just return <code>$output</code>? And whats happens with this variable after return? Still uses a memory? </p>