试图注销但不断收到错误警告：第4行除零？

Question

been playing around with the small project to log out but each time I'm trying to log out giving this error:

Warning: Division by zero in /home2/beastly/public_html/test/logout.php on line 4

Warning: Cannot modify header information - headers already sent by (output started at /home2/beastly/public_html/test/logout.php:4) in /home2/beastly/public_html/test/logout.php on line 4

Warning: session_destroy() [function.session-destroy]: Trying to destroy uninitialized session in /home2/beastly/public_html/test/logout.php on line 8 You will be forwarded in back to login screen If not Click Here

<?php
//remove PHPSESSID from browser
if ( isset( $_COOKIE[session_name()] ) )
setcookie( session_name(), “â€, time()-3600, “/†);
//clear session from globals
$_SESSION = array();
//clear session from disk
session_destroy(); here

Answer 1

Your PHP code appears to have been mangled by an incorrect character set. If you look at line 4:

setcookie( session_name(), “â€, time()-3600, “/†);

You'll notice that there is a division operator there.

If you turn on all errors, you'll see that it's also complaining about the "undefined constants" “â€, “, and â€. That last one, in a numeric context, resolves to zero, which is why you're getting the divide-by-zero error.

If you're getting the error Trying to destroy uninitialized session when you're calling session_destroy(), then the session doesn't actually exist. Did you call session_start() beforehand? You can't manipulate the session until you do.