title: Is it a good practice to unset cookie expire parameter?
body: <p>I see the usage of the following code snippet:</p>
  
  <pre><code>    $cookieexpiry=(time()+21600);
      setcookie("rwphp","$cookieid",$cookieexpiry,"/",$_SERVER["HTTP_HOST"],0);
      unset($cookieexpiry);
  </code></pre>
  
  <p>Q1> My question is whether or not this is a good practice to unset $cookieexpiry.</p>
  
  <p>Q2> In general cases, when should I unset variables?</p>
  
  <p>Thank you</p>