Removing array key from multidimensional Arrays php

array_filter is great for removing things you don't want from arrays.

$cart = array_filter($cart, function($x) { return $x['id'] != 15; });

If you want to use a variable to determine which id to remove rather than including it in the array_filter callback, you can use your variable in the function like this:

$value = 15;
$cart = array_filter($cart, function($x) use ($value) { return $x['id'] != $value; });

you can use:

foreach($array as $key => $item) {
  if ($item['id'] === $value) {
    unset($array[$key]);
  }
}

There are a lot of weird array functions in PHP, but many of these requests are solved with very simple foreach loops...

$value = 15;
foreach ($cart as $i => $v) {
    if ($v['id'] == $value) {
        unset($cart[$i]);
    }
}

If $value is not in the array at all, nothing will happen. If $value is in the array, the entire index will be deleted (unset).