Filter multidimensional array by equal values in sub array (PHP)

Question

I need to filter a multidimensional array by the value of a sub-array which might be on a different position each time.

The following array

array(3) {
      [147]=>
      array(2) {
        [0]=>
        int(4)
        [1]=>
        string(3) "req"
      }
      [199]=>
      array(2) {
        [0]=>
        int(5)
        [1]=>
        string(3) "opt"
      }
      [212]=>
      array(3) {
        [0]=>
        int(2)
        [1]=>
        int(5)
        [2]=>
        string(3) "req"
      }

needs to be split into these arrays.

Array 1:

array(2) {
      [147]=>
      array(2) {
        [0]=>
        int(4)
        [1]=>
        string(3) "req"
      }
      [212]=>
      array(3) {
        [0]=>
        int(2)
        [1]=>
        int(5)
        [2]=>
        string(3) "req"
      }

Array 2:

array(1) {
      [199]=>
      array(2) {
        [0]=>
        int(5)
        [1]=>
        string(3) "opt"
      }

I know of array_filter() but can´t figure out the function inside array_filter() that gives me the desired result.

I tried

$req = array_filter($my_array, function ($v, $k) {
    return $v == 'req';
}, ARRAY_FILTER_USE_BOTH);

I also tried

function filter_my_array($my_array, $search_term) {
  $new_array = array();
  foreach ($my_array as $subarray) {
    if (in_array($search_term, $subarray)) {
       $new_array[] = $subarray;
    }
  }
  return $new_array; 
} 

$req = filter_my_array($array, 'req');

Both approaches do not work.

Answer 1

You can create two arrays with the help of filtering by necessary values. You can use array_filter function to it, but you should find a necessary value in each element that passed to array_filter function.

For example, finding 'req' value

$req = array_filter($my_array, function ($v) {
    return in_array('req', $v);
});

For example, finding 'opt' value

$opt = array_filter($my_array, function ($v) {
    return in_array('opt', $v);
});

I used in_array function to finding values because each element is an array that has different quantity of elements

Answer 2

This seems to work for me:

function filter_my_array($my_array, $search_term) {
    $required_array = [];
    $filtered_array = [];
    foreach ($my_array as $key => $subarray) {
        $found_flag = false;
        foreach ($subarray as $cur_subarray) {
            if ($cur_subarray == $search_term) {
                $found_flag = true;
                break;
            }
        }

        if ($found_flag == true) {
            $required_array[$key] = $subarray;
        } else {
            $filtered_array[$key] = $subarray;
        }
    }

    return [$required_array, $filtered_array];
}

To retrieve the required array and the filtered array, call the function as follows:

list($required_array, $filtered_array) = filter_my_array($my_array, 'req');

where $my_array holds the array in your example.