Parse formatted strings containing 3 delimiters to create multiple flat arrays

Question

I have strings in following format:

$strings[1] = cat:others;id:4,9,13
$strings[2] = id:4,9,13;cat:electric-products
$strings[3] = id:4,9,13;cat:foods;
$strings[4] = cat:drinks,foods;

where cat means category and id is identity number of a product.

I want to split these strings and convert into arrays $cats = array('others'); and $ids = array('4','9','13');

I know that it can be done by foreach and explode function through multiple steps. I think I am somewhere near, but the following code does not work.

Also, I wonder if it can be done by preg_match or preg_split in fewer steps. Or any other simpler method.

foreach ($strings as $key=>$string) {
   $temps = explode(';', $string);
   foreach($temps as $temp) {
      $tempnest = explode(':', $temp);
      $array[$tempnest[0]] .= explode(',', $tempnest[1]);
   }
}

My desired result should be:

$cats = ['others', 'electric-products', 'foods', 'drinks';

and

$ids = ['4','9','13'];

Answer 1

One option could be doing a string compare for the first item after explode for cat and id to set the values to the right array.

$strings = ["cat:others;id:4,9,13", "id:4,9,13;cat:electric-products", "id:4,9,13;cat:foods", "cat:drinks,foods"];

foreach ($strings as $key=>$string) {
    $temps = explode(';', $string);
    $cats = [];
    $ids = [];
    foreach ($temps as $temp) {
        $tempnest = explode(':', $temp);

        if ($tempnest[0] === "cat") {
            $cats = explode(',', $tempnest[1]);
        }
        if ($tempnest[0] === "id") {
            $ids = explode(',', $tempnest[1]);
        }
    }
    print_r($cats);
    print_r($ids);
}

Php demo

Output for the first item would for example look like

Array
(
    [0] => others
)
Array
(
    [0] => 4
    [1] => 9
    [2] => 13
)

---

If you want to aggregate all the values in 2 arrays, you can array_merge the results, and at the end get the unique values using array_unique.

$strings = ["cat:others;id:4,9,13", "id:4,9,13;cat:electric-products", "id:4,9,13;cat:foods", "cat:drinks,foods"];
$cats = [];
$ids = [];
foreach ($strings as $key=>$string) {
    $temps = explode(';', $string);

    foreach ($temps as $temp) {
        $tempnest = explode(':', $temp);

        if ($tempnest[0] === "cat") {
            $cats = array_merge(explode(',', $tempnest[1]), $cats);
        }
        if ($tempnest[0] === "id") {
            $ids = array_merge(explode(',', $tempnest[1]), $ids);
        }
    }

}
print_r(array_unique($cats));
print_r(array_unique($ids));

Output

Array
(
    [0] => drinks
    [1] => foods
    [3] => electric-products
    [4] => others
)
Array
(
    [0] => 4
    [1] => 9
    [2] => 13
)

Php demo