removing array from multidimensional array - php

Question

I have a session that looks like this:
array(3) {
["counter"]=>
int(0)
["currentItem"]=>
string(1) "2"
["addedToCart"]=>
array(12) {
[0]=>
array(11) {
["aantal"]=>
int(1)
["id"]=>
string(1) "1"
["filmtitel"]=>
string(11) "a_bugs_life"
["film_id"]=>
string(1) "2"
["zaal_id"]=>
string(1) "1"
["zaaltitel"]=>
string(6) "zaal 1"
["tijdstip"]=>
string(8) "15:00:00"
["stoeltjes"]=>
string(2) "21"
["dag"]=>
string(8) "woensdag"
["verwijder"]=>
int(2)
["vertoningId"]=>
string(1) "3"
}
[1]=>
array(11) {
["aantal"]=>
int(1)
["id"]=>
string(1) "1"
["filmtitel"]=>
string(11) "a_bugs_life"
["film_id"]=>
string(1) "2"
["zaal_id"]=>
string(1) "1"
["zaaltitel"]=>
string(6) "zaal 1"
["tijdstip"]=>
string(8) "15:00:00"
["stoeltjes"]=>
string(1) "7"
["dag"]=>
string(8) "woensdag"
["verwijder"]=>
int(2)
["vertoningId"]=>
string(1) "3"
}
[2]=>
array(11) {
["aantal"]=>
int(1)
["id"]=>
string(1) "1"
["filmtitel"]=>
string(11) "a_bugs_life"
["film_id"]=>
string(1) "2"
["zaal_id"]=>
string(1) "1"
["zaaltitel"]=>
string(6) "zaal 1"
["tijdstip"]=>
string(8) "15:00:00"
["stoeltjes"]=>
string(2) "22"
["dag"]=>
string(8) "woensdag"
["verwijder"]=>
int(2)
["vertoningId"]=>
string(1) "3"
}
}
}
Now, from $_SESSION['addedToCart] I would like to remove arrays if they meet to certain conditions. I have tried the following.
foreach ($_SESSION["addedToCart"] as $arr) {
if ($arr["stoeltjes"] == $stoeltje && $arr['film_id'] == $id) {
unset($arr);
}
}
This doesn't seem to work, it doesn't remove anything, I did a var_dump to check if the variables $stoeltje and $id were fine and they were fine so that cant be the problem.
Am I able to use unset in this kind of situation?

Answer 1

foreach ($_SESSION["addedToCart"] as &$arr)
& turns your variable into a reference instead of a copy. Normally this would be sufficient. unset() only works on data within the current scope (so your foreach loop) leaving the original unchanged (See unset() for details).
Instead you can do:
foreach ($_SESSION["addedToCart"] as $key => $val)
{
if ($val["stoeltjes"] == $stoeltje && $val['film_id'] == $id) {
unset($_SESSION["addedToCart"][$key]);
}
}

Answer 2

Even if the suggested way with the reference should work normally, here's an example without it:
foreach ($_SESSION["addedToCart"] as $key => $arr) {
if ($arr["stoeltjes"] == $stoeltje && $arr['film_id'] == $id) {
unset($_SESSION["addedToCart"][$key]);
}
}

Answer 3

It doesn't work, because foreach is working on a copy, therefore $arr is just a copy of each element in the main table.
from php.net:
As of PHP 5, you can easily modify array's elements by preceding $value with &. This will assign reference instead of copying the value.
$arr = array(1, 2, 3, 4);
foreach ($arr as &$value) {
$value = $value * 2;
}
// $arr is now array(2, 4, 6, 8)

Answer 4

Try this:
$arr = array(1, 2, 3, 4);
foreach ($arr as $key => &$value) {
if ($value == 2)
{
unset($arr[$key]);
}
}
print_r($arr);

Answer 5

remove_array_key("film_id", $array);
function remove_array_key($key, &$array)
{
$result = array_key_exists($key, $array);
if ($result) {
unset($array[$key]);
return $array;
}
foreach ($array as &$v) {
if (is_array($v)) {
$result = remove_array_key($key, $v);
}
if (is_array($result)) {
unset($v[$key]);
return $array;
}
}
return false;
}
Link to Github Explanation