Unset array element and reseting array values in PHP - php

Question

So I have 2 files. In file 1 I have a table and there I randomly select some fields and store (store in session) them in an array of 2D arrays. When I click on the cell I send this data to my file 2 where I want to check if I clicked on a randomly selected array or not and if I did, I want to remove this 2D array from an main array.
But as soon as I click on one of the selected arrays, the array crashes.
File 1 PHP stuff immportant for this:
session_start();
$_SESSION['arrays'] = $stack ;
File 2 PHP:
session_start();
if (isset($_SESSION['arrays'])) {
$stack = $_SESSION['arrays'];
for ($i = 0; $i< count($stack);$i++){
if($cooridnates == $stack[$i]){
unset($stack[$i]);
array_values($stack);
$i--;
$Result = true;
break;
}
}
$_SESSION['arrays'] = $stack ;
I am suspecting the error might be in 2 things:
count($stack) used, but I don't believe this is the main reason.
The way I store session.
I have tried using manuals from W3Schools and official PHP website and also SOF, but with no use.
But still, I am not sure if the array_values() and unset() is working correctly since the thing chrashes and I can't test it correctly.
I would appreciate any tips.

Answer 1

You need to assign the result of array_values($stack); back to the $stack variable.
$stack = array_values($stack);
There's also no need to use $i-- when you do this, since you're breaking out of the loop after you find a match.
Instead of a loop, you can use array_search():
$pos = array_search($coordinates, $stack);
if ($pos !=== false) {
unset $stack[$pos];
$Result = true;
$stack = array_values($stack);
$_SESSION['arrays'] = $stack;
}

Answer 2

you can do this like that by using foreach loop:
session_start();
if (!empty($_SESSION['arrays'])) {
foreach( $_SESSION['arrays'] as $key => $val){
if($cooridnates == $val){
unset($_SESSION['arrays'][$key]); // if you want this removed value then assign it a variable before unsetting the array
$Result = true;
break;
}
}
}