multidimensional array array_sum

Question

I have seen various posted about this question so am aware some answers to this may exist. however I am none the wiser after reading these.

I have an array that is

Answer 1

array_sum_multidimensional Helper function

if (!function_exists('array_sum_multidimensional')) {
    /**
     * returns the sum of a element from an array of arrays
     */

    function array_sum_multidimensional(array $array, $elementKey){

        $sum = 0;

        foreach($array as $key => $value) {
            $sum += $value[ $elementKey ];
        }

        return $sum;
    }
}