php check if element exist through session array - php

Question

How can I loop through set of session array and check if $_session['items'][1][p_alt-variation-1] and so on, are exist? the [p_alt-variation-{n}] elements are dynamic if certain item has these add-on variations, so it could be as much as more than 1
print_r($_session['items'])
Array
(
[0] => Array
(
[p_name] => Hovid PetSep
[p_code] => 336910
[p_coverImg] => 14-1460428610-ulNvG.jpg
[p_id] => 14
[p_price] => 24.50
[p_qty] => 2
)
[1] => Array
(
[p_name] => X-Dot Motorbike Helmet G88 + Bogo Visor (Tinted)
[p_code] => 2102649
[p_coverImg] => 12-1460446199-wI5qx.png
[p_id] => 12
[p_price] => 68.00
[p_alt-variation-1] => Red
[p_alt-variation-2] => L
[p_qty] => 1
)
)
I want to show for user if certain item has various variations in their cart if exist, how to look for element in array if contains string like [p_alt-variation-{n}] through?
I use foreach($_SESSION['items'] as $cart_item){ ... } to loop all cart items to show item's info.
Thanks for advice.

Answer 1

Not a regex guru, but you could just get the keys and check using preg_grep. If it has more than one key for that keyword, just count the results.
Here's the idea:
foreach($_SESSION['items'] as $cart_item) { // loop the items
$keys = array_keys($cart_item); // get the keys of the current batch
// make the expression
$matches = preg_grep('~^p_alt\-variation\-\d+~i', $keys); // simply just checking the key name with has a number in the end, adjust to your liking
if(count($matches) > 1) { // if it has more than one, or just change this to how many do you want
echo 'has more than one variation';
}
}
If you wanted to use some of that keys, just use the results that was found inside $matches:
if(count($matches) > 1) {
foreach($matches as $matched_key) {
echo $cart_item[$matched_key];
}
}

Answer 2

The session variables are just like any other array values; you can always use isset function. Please refer: http://php.net/manual/en/function.isset.php