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

Just a way to do it:

$sum = 0;

foreach($account_invoices as $num => $values) {
    $sum += $values[ 'vatAmount' ];
}

Answer 2

You could use array_map first to collect the vatAmout value.

$sum = array_sum(array_map(function($var) {
  return $var['vatAmout'];
}, $account_invoices));

Answer 3

You can't do this directly with array_sum, which would sum everything in the array.

You can do it with a loop:

$sum = 0;
foreach($items as $item)
    $sum += $item['vatAmount'];

or you can filter the array (in this case it isn't very convenient, but if you had to calculate, say, S&H expenses plus VAT plus..., from each single item, and then sum...):

// Input: an array (element #n of array of arrays), output: VAT field
function getVAT($item)
{
    return $item['vatAmount'];
}

// Array with all VATs
$vats = array_map('getVAT', $items);

$sum = array_sum($vats);

Answer 4

Also you can do this (if you like array_sum function):

foreach($account_invoices as $num => $values) {
    $vatAmount[] = $values[ 'vatAmount' ];
}

$Total = array_sum($vatAmount);

Answer 5

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;
    }
}

Answer 6

If you have PHP 5.5+ you can do this without looping or using a callback (since function calls are relatively expensive) ... just use:

$sum = array_sum(array_column($account_invoices, 'vatAmount'));