How to sum all column values in multi-dimensional array?

It can also be done using array_map :

$rArray = array(
    0 => array(
        'gozhi' => 2,
        'uzorong' => 1,
        'ngangla' => 4,
        'langthel' => 5
    ),
    1 => array(
        'gozhi' => 5,
        'uzorong' => 0,
        'ngangla' => 3,
        'langthel' => 2
    ),
    2 => array(
        'gozhi' => 3,
        'uzorong' => 0,
        'ngangla' => 1,
        'langthel' => 3
    ),
);

$sumResult = call_user_func_array('array_map', array_merge(['sum'], $rArray));

function sum()
{
    return array_sum(func_get_args());
}

Go through each item of the array and sum values to previous values if they exist, if not just assign the value.

<?php
$array = 
[
    [
        'a'=>1,
        'b'=>1,
        'c'=>1,
    ],
    [
        'a'=>2,
        'b'=>2,
    ],
    [
        'a'=>3,
        'd'=>3,
    ]
];

$result = array_reduce($array, function($carry, $item) {
    foreach($item as $k => $v)
        $carry[$k] = $v + ($carry[$k] ?? 0);

    return $carry;
}, []);

print_r($result);

Output:

Array
(
    [a] => 6
    [b] => 3
    [c] => 1
    [d] => 3
)

Or just loop through each sub array, and group the values for each column. Eventually summing them:

foreach($array as $subarray)
    foreach($subarray as $key => $value)
        $grouped[$key][] = $value;

$sums = array_map('array_sum', $grouped);

We need to check first if array key does exist.

CODE:

$sum = array();
foreach ($array as $key => $sub_array) {
    foreach ($sub_array as $sub_key => $value) {

        //If array key doesn't exists then create and initize first before we add a value.
        //Without this we will have an Undefined index error.
        if( ! array_key_exists($sub_key, $sum)) $sum[$sub_key] = 0;

        //Add Value
        $sum[$sub_key]+=$value;
    }
}
print_r($sum);

OUTPUT With Array Key Validation:

Array
(
    [gozhi] => 10
    [uzorong] => 1
    [ngangla] => 8
    [langthel] => 10
)

OUTPUT Without Array Key Validation:

Notice: Undefined index: gozhi in F:\web\index.php on line 37

Notice: Undefined index: uzorong in F:\web\index.php on line 37

Notice: Undefined index: ngangla in F:\web\index.php on line 37

Notice: Undefined index: langthel in F:\web\index.php on line 37

Array
(
    [gozhi] => 10
    [uzorong] => 1
    [ngangla] => 8
    [langthel] => 10
)

This is a bad practice although it prints the output. Always check first if key does exist.

Simple example with array_reduce()

$numbers = [10,20,30];

$total = 0;

foreach ($numbers as $number) {
    $total += $number;
}

echo $total; // 60

=>

$numbers = [10,20,30];

$total  = array_reduce($numbers, function ($previous, $current) {
    return $previous + $current;
});

echo $total; // 60

With assoc array:

$carts = [
    ['item' => 'A', 'qty' => 2, 'price' => 10],
    ['item' => 'B', 'qty' => 3, 'price' => 20],
    ['item' => 'C', 'qty' => 5, 'price' => 30]
];


$total = array_reduce(
    $carts,
    function ($prev, $item) {
        return $prev + $item['qty'] * $item['price'];
    }
);

echo $total; // 155

More info => https://www.phptutorial.net/php-tutorial/php-array_reduce/

this works great on my laravel project

print_r($Array); // your original array

$_SUM = [];

// count($Array[0]) => if the number of keys are equall in all arrays then do a count of index 0 etc.
for ($i=0; $i < count($Array[0]); $i++) {
    $_SUM[] = $Array[0][$i] + $Array[1][$i]; // do a for loop on the count 
}

print_r($_SUM); // get a sumed up array

$sumArray = array();

foreach ($myArray as $k=>$subArray) {
  foreach ($subArray as $id=>$value) {
    if(!isset($sumArray[$id])){
     $sumArray[$id] =$value;
    }else {
     $sumArray[$id]+=$value;
    }
  }
}

print_r($sumArray);

`

For example, you can pluck all fields from a result like this below.

I am picking out the 'balance' from an array and save to a variable

$kii =   $user->pluck('balance');

then on the next line u can sum like this:

$sum =  $kii->sum(); 

Hope it helps.

Code here:

        $temp_arr = [];
        foreach ($a as $k => $v) {
            if(!is_null($v)) {
                $sum = isset($temp_arr[$v[0]]) ? ((int)$v[5] + $sum) : (int)$v[5];
                $temp_arr[$v[0]] = $sum;
            }
        }
        return $temp_arr;

Result:

{SEQ_OK: 1328,SEQ_ERROR: 561}