uncertain variables in php
<pre><code>if($a == 4){
   echo 'ok';
}
</code></pre>

<p>Now displays an error because $a variable is not defined.
my decision:</p>

<pre><code>if(isset($a)){
    if($a == 4){
    echo 'ok';
    }
}
</code></pre>

<p>But maybe there are better solutions?</p>
