在回声中取消设置会话导致问题

Question

I am getting the following error and can not figure out why. I've been staring at this for too long..

Error:

Parse error: syntax error, unexpected T_UNSET in blah/blah/blah

My code:

Essentially, I am trying to give the user the ability to clear a session via clicking a link. Not sure where I am going wrong within my syntax... Any help would be much appreciated!

NOTE: Yes, my code is within php blocks

echo "<span><a href='" . unset($_SESSION['vertical']) . "'>clear "
 . $vertical . "</a></span>";

Thanks in advance!

Answer 1

You cannot call PHP functions after the page has finished loading. PHP is a server-side technology and works on the server, not on the client's computer. Which means, you won't be able to call a PHP function without sending the details to the script.

If you're trying to trigger the unset function when the user clicks the link, then you could create a link to a script where you unset the $_SESSION variable:

<span><a href='somepage.php?somevar=42'>foo</a></span>

When the user clicks on the link, they'll be taken to somepage.php. Now, you can check if the somevar key is set and then unset the session in the script:

<?php
session_start();

if (isset($_GET['somevar'])) {
    unset($_SESSION['vertical']);
}

If you want to do this without a page refresh, then you might want to take a look at AJAX.