replacing a variable of a multidimensional session array - php

Question

I have a multidimensional session array that is set. Session start is called at the top of the file and all the fields are set as the examples
//set variables
$locked="unlocked";$name="BMX";$sport_activity="sport";$quantity="1";$price="600";
//set variables to array
$sports_array = array(0 => array(
'i_locked' => $locked,
'i_name' => $name,
'i_quantity' => $quantity,
'i_price' => $price,
'i_sport_activity' => $sport_activity,
'i_base_price' => $price));
//set multidimensional session array
$_SESSION["activity"][] = $sports_array;
Then the array is called in a PHP loop.
$arrayID = -1;
//foreach loop
foreach($_SESSION['activity'] as $key){
foreach($key as $list){
$arrayID += 1;
?>
//echo all the array items individually in separate divs
<form>
<div>
<?php echo $list['i_locked']?>
</div>
// ..... etc
<input type="hidden" name="ArrayNum" value="<?=$arrayID?>">
<input type='submit' name='Confirm_button'>
</form>
All of this works, what i would like to then do is change a variable and add new ones.
I have come across array_push() for adding new fields onto an array. And i have tried the following below, but either it adds an entire array stack or delete's the array stack.
if(isset($_POST["Confirm_button"])){
$time = 'pm';
$date = 'feb';
$_SESSION['activity'][$_POST['ArrayNum']]['i_locked'] = 'locked';
array_push($_SESSION['activity'][$_POST['ArrayNum']],'i_time'=>$time,'i_date'=>$date);
}
Any help or a point in the right direction for best practices would be most appreciated
************************* Re- Edit ****************************************
Credit to #Suchit Kumar
Was able to get the problem fixed based on his help.
The first issue of changing an element of the array works with the following code. And correctly finds the element that needs changing.
$_SESSION['activity'][$_POST['ArrayNum']][0]['i_locked'] = 'locked';
The second issue of adding new elements to the array works with the following code.
$time = 'pm';
$date = 'feb';
$_SESSION['activity'][$_POST['ArrayNum']][0]['i_time'] = $time;
$_SESSION['activity'][$_POST['ArrayNum']][0]['i_time'] = $date;

Answer 1

I think you can not use key value pair in array_push without using array('key'=>'value') format. in this case you have to do something like this dynamically:
and the way you are creating $_SESSION["activity"][]=$sports_array;.your array will come on index ['activity'][0][0].
IT is an Example to point out the problem But you need to follow this Dynamically by creating dynamic indexes.
<?php
$time = 'pm';
$date = 'feb';
$_SESSION['activity'][0][0]['i_time']=$time;// when already some elements are there with the key
$_SESSION['activity'][0][0]['i_date']=$date;
echo "<pre>";
print_r($_SESSION);
echo "<pre>";
if you want to add another array do $_SESSION['activity']:
$time1 = 'am';
$date1 = 'mar';
array_push($_SESSION['activity'][$_POST['ArrayNum']],array('i_new'=>$time1,'i_new1'=>$date1));//createing new key and pussing the array.
to update any value in an array do this:
check if:
if(isset($_SESSION['activity'][0][1]['i_time'])){// you can use foreach to access eack key value pair before if condition
$_SESSION['activity'][0][1]['i_time']=$newtime;
}
?>
NOTE: this is only to show your how you will do in your original code.