How to Efficiently Calculate Column Totals in Irregular Multi-Dimensional Arrays?

How to Calculate Column Totals in a Multi-Dimensional Array

Consider a multi-dimensional array where elements are arranged in rows and columns, but the key sets may vary dynamically. The task is to calculate the sum of values within each column, regardless of key variations.

Array_Walk_Recursive Method

For a general solution where inner arrays can have unique keys, utilize array_walk_recursive():

$final = array();

array_walk_recursive($input, function($item, $key) use (&$final){
    $final[$key] = isset($final[$key]) ?  $item + $final[$key] : $item;
});

Array_Column Method

If specific key values need to be summed, array_column() can be used:

array_sum(array_column($input, 'gozhi')); // Sums the 'gozhi' column

For Uniform Inner Arrays

If all inner arrays have the same keys, obtain the initial key structure:

$final = array_shift($input);

foreach ($final as $key => &$value){
   $value += array_sum(array_column($input, $key));
}    

unset($value);

General Case with Array_Column

Extract unique keys and perform column sums:

$final = array();

foreach($input as $value)
    $final = array_merge($final, $value);

foreach($final as $key => &$value)
    $value = array_sum(array_column($input, $key));

unset($value);

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