PHP将GET var附加到SESSION

Question

I wanted to make a simple shopping cart which takes a $_GET variable and puts it in the $_SESSION variable. The code I have tried is this:

<?php 
    session_start();
    if (is_numeric($_GET['add'])) $_SESSION[(string)$_GET['add']] = 1; ?>

Because my item ids are numeric so I check first to stop random things to be added to the session variable. I then then do a var_dump to see the result. The first time I run the code with ?add=102 I get:

array(1) { [102]=> int(1) }

I then run the script again with ?add=108 I get:

array(1) { [108]=> int(1) }

What I want is:

array(2) { ["102"]=> int(1), ["108"]=> int(1) }

What am I doing wrong? My concept is to convert the $_GET variable to a string and store the quantity 1 and the string value of $_GET in $_SESSION associatively. This should allow me to add as many items as long as their id is not the same, which is what I want.

Here is alternatives I have tried:

strval($_GET['add']), 
(string)($_GET['add']), 
$_GET['add']

Nothing seems to work.

Any help would be appreciated.

Answer 1

You cannot use $_SESSION keys that are numeric. Create another array in the session, eg $_SESSION['items']

Then:

session_start();
if(is_numeric($_GET['add']))
{
    $_SESSION['items'][(string)$_GET['add']] = 1;
}

It's much easier to iterate over this items array later, when you have other information in your session.

Answer 2

I realise this is an amalgamation of Satya's comment and mthie's answer but the complete answer should I think be

1. You would be well advised to encapsulate the array you are building in its own named location and
2. you need to add to the array each time rather than overwrite it

so try

<?php
    session_start();
    if(is_numeric($_GET['add'])) {
       $_SESSION['add'][][(string)$_GET['add']] = 1;
    }
?>