pHp会话错误？

Question

I've been trying to figure out why my code isn't working on my PC at home using XAMPP 1.8.2 while at work I've been using 1.7.2. I get the following error

Fatal error: Call to undefined function session_is_registered() in C:\xampp\htdocs\loginscript\session1.php on line 5

What I have on line 5.

if(!session_is_registered(username)){
header("location:index.php");
}

I would imagine it having to do something with pHp version? Cheers

A user has requested to see my code..

<?php 
session_start()
//--- Authenticate code begins here ---
//checks if the login session is true
if(!session_is_registered(username));{
header("location:index.php");
}
$username = $_SESSION['username'];

// --- Authenticate code ends here ---


 include ('header.php'); ?> 

Answer 1

As pointed out by Halloei in the comments, you said at home you are using Xampp 1.8.2 and at work 1.7.2 - if you have a look at the Xampp version history 1.8.2 comes with PHP 5.4 whereas 1.7.2 comes with PHP 5.3 and the session_is_registered function was DEPRECATED as of PHP 5.3.0 and REMOVED as of PHP 5.4.0. This is the cause of the error you are seeing.

To correct this you can update your code to something like the following:

<?php 
session_start();

//--- Authenticate code begins here ---

//checks if the login session is true
if (!isset($_SESSION['username']))
{
    header("location:index.php");
}
$username = $_SESSION['username'];

// --- Authenticate code ends here ---

include ('header.php'); 
?> 

This uses isset to check if the value username is set in the session array.