PHP会话变量没有注册

Question

I've been searching all day and found several similar issues, but none have resolved my problem. As the title states I'm having trouble with session variables not being "saved" - i.e they work only like local variables. What I'm trying to accomplish:

index page with function "ABC" not running by defualt - link to myscript.php to activate session variable of type boolean - myscript.php checks if session variable is set, if not turns it to true. Otherwise turns it to false: index page should now have function "ABC" activated.

So, here is the funny thing. This worked like a charm earlier today, but after a random refresh, now it don't. Thinking this was a session trouble, I added a session ID but found that the session ID is correct / the same on both the index page and myscript.php.

I've also tried to enable error reporting and found that I'm getting the "Undefined index: showAll in C:\xampp\htdocs\kelvin\ext\set_date.php on line 15". Which is weired, seing as i use the issset function to avoid just that.

myscript.php

<?php
session_start();
echo "Session ID: " . session_id(); //Is the same as on the index page where the script is being called.
---------------
//Sets speed mode on or off (simple or extensive listing).
if(!isset($_SESSION['showAll']))
{    
    $_SESSION['showAll'] == TRUE;
}
 else {
    if($_SESSION['showAll'] == TRUE)
    {
        $_SESSION['showAll'] = FALSE;
    }
    else
    {
        $_SESSION['showAll'] = TRUE;
    }
}
header('location:../index.php');
?>

In advance, thanks for any input :)

Answer 1

Your problem might be here:

if (!isset($_SESSION['showAll'])) {
  $_SESSION['showAll'] == TRUE;
}

The double equal sign (==) checks for equality, but does not set anything.

Try replacing it with the single equal sign (=).

---

Also, your logic can be condensed considerably:

if (!isset($_SESSION['showAll'])) {    
  $_SESSION['showAll'] = true;
} else {
  $_SESSION['showAll'] = !$_SESSION['showAll'];
}

You are just swapping the value of $_SESSION['showAll'].