PHP null var exists
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/3803282/check-if-value-isset-and-null">Check if value isset and null</a>  </p>
</blockquote>



<p>If I have <code>$v = NULL;</code> how can I check  that <code>$v</code> is exists and it's <code>NULL</code>?</p>

<pre><code>isset($v) =&gt; false //because of NULL, but $v exists
</code></pre>
