session variable name as a variable? - php

Question

I try to make a session variable where the session variable name should be diffrent, and therefore i make the session variable name a variable name:
$nummer = $_POST['nummer'];
$num = $nummer;
$vareInfo = array(
"vareNummer" => "$nummer",
"vareNavn" => "$vare",
"varePris" => $pris,
"vareBillede" => $VarBillede,
"vareAntal" => $antal
);
$_SESSION[$num] = $vareInfo;
$_SESSION[$pris] = "hukabuka";
but i dosen't work, i just changeching the the other sessioen to the new value?
it output this:
Array ( [vareNummer] => 182162
[vareNavn] => Solsikke
[varePris] => 120
[vareBillede] => 63c7cba6cac6d7.24544415.jpg
[vareAntal] => 1
)
and next time i run it it changing it instead of making a new

Answer 1

To prevent that your session gets overwritten add a check if the session already exists.
That way it only gets created once for each unique $num
$nummer = $_POST['nummer'];
$num = $nummer;
$vareInfo = array(
"vareNummer" => "$nummer",
"vareNavn" => "$vare",
"varePris" => $pris,
"vareBillede" => $VarBillede,
"vareAntal" => $antal
);
if(!isset($_SESSION[$num])){
$_SESSION[$num] = $vareInfo;
}
if(!isset($_SESSION[$pris])){
$_SESSION[$pris] = "hukabuka";
}

Answer 2

An example how this can be made to work (using PHP 8.2):
my_form.html:
<form action="do_stuff.php" method="POST">
<input id="data1" name="data1" type="text">
<input id="data2" name="data2" type="text">
<input type="submit" value="Do">
</form>
do_stuff.php:
<?php
session_start();
$nummer = $_POST['data1'];
$num = $nummer;
$pris = $_POST['data2'];
$vareInfo = array(
"vareNummer" => "$nummer",
"varePris" => $pris
);
$_SESSION['my_data'][$num] = $vareInfo;
$_SESSION['my_data'][$pris] = "hukabuka";
// or, the session variables can be set using a prefix:
//$_SESSION['my_data_' . $num] = $vareInfo;
?>
EDIT ADD:
An example session data from posting twice from the form using two unique data1 values would be as shown below. The values are 1234 and 7890.
Array (
[my_data] =>
Array (
[1234] => Array ( [vareNummer] => 1234 [varePris] => 55 )
[55] => hukabuka
[7890] => Array ( [vareNummer] => 7890 [varePris] => 99 )
[99] => hukabuka
)
)

Answer 3

Check the session with that variable, if already set with that index then do not over write the session value
you can use either isset or !empty in php
<?php
$nummer = $_POST['nummer'];
$num = $nummer;
$vareInfo = array(
"vareNummer" => "$nummer",
"vareNavn" => "$vare",
"varePris" => $pris,
"vareBillede" => $VarBillede,
"vareAntal" => $antal
);
if(!empty($_SSESSION[$num])) {
$_SESSION[$num] = $vareInfo;
}
if(!empty($_SESSION[$pris])) {
$_SESSION[$pris] = "hukabuka";
}
?>