传递PHP会话

Question

I am having problems passing session variables all of the sudden and I don't know what I'm doing wrong. See my test code below for createSession.php and passingSession.php. I can create the session ok on createSession.php but when I click the link to see if the session is passing to passingSession.php, the session is now empty.

Note: session_start() is the very first thing on each page. No leading white space of any kind.

createSession.php

session_start();

$_SESSION['aID'] =  time();

if($_SESSION['aID']==""){
    echo "Session is empty. There is a problem creating sessions";
}else{
    echo "Session = ".$_SESSION['aID']." There is no problem creating sessions.  <a href='passingSession.php'>Click Here</a> to see if sessions are passing ok.";   
}

passingSession.php

session_start();

if($_SESSION['aID']==""){
    echo "Session is empty. There is a problem passing sessions.";
}else{
    echo "Session = ".$_SESSION['aID'].". Passing sessions is ok."; 
}

Answer 1

Don't use if($_SESSION['aID']=="") to test if a session exists but use isset(). You are comparing your session variable to an empty string which is different from an unset variable.

Use something like this:

session_start();

if(!isset($_SESSION['aID'])){
    echo "Session is empty. There is a problem passing sessions.";
}else{
    echo "Session = ".$_SESSION['aID'].". Passing sessions is ok."; 
}