Check if variable returns true
<p>I want to echo 'success' if the variable is true. (I originally wrote "returns true" which only applies to functions.</p>

<pre><code>$add_visits = add_post_meta($id, 'piwik_visits', $nb_visits, true);
if($add_visits == true){
         echo 'success';
}
</code></pre>

<p>Is this the equivalent of</p>

<pre><code>$add_visits = add_post_meta($id, 'piwik_visits', $nb_visits, true);
if($add_visits){
         echo 'success';
}
</code></pre>

<p>Or does $add_visits exist whether it is 'true' or 'false';</p>
