php计算每10个数组元素的总数

Array ( 
    [0] => Array ( 
        [amount_paid] => 2050.00 
    )
    [1] => Array ( 
        [amount_paid] => 2050.00 
    ) 
    [2] => Array ( 
        [amount_paid] => 2050.00 
    ) 
    [3] => Array ( 
        [amount_paid] => 2050.00 
    ) 
    [4] => Array ( 
        [amount_paid] => 2050.00 
    ) 
    [5] => Array ( 
        [amount_paid] => 2050.00 
    ) 
    [6] => Array ( 
        [amount_paid] => 2050.00 
    ) 
    [7] => Array ( 
        [amount_paid] => 2050.00 
    ) 
    [8] => Array ( 
        [amount_paid] => 2050.00 
    ) 
    [9] => Array ( 
        [amount_paid] => 2050.00 
    ) 
    [10] => Array ( 
        [amount_paid] => 2050.00 
    ) 
    [11] => Array ( 
        [amount_paid] => 2050.00 
    ) 
    [12] => Array ( 
        [amount_paid] => 2050.00 
    ) 
    [13] => Array ( 
        [amount_paid] => 2050.00 
    ) 

) 

I have this example of array in php. I want to sum up every 10 paid amount.

Example is sum index 0-9 , 10 - 19 and so on

What I tried is only for first 10 and I cant think how to handle for every 10 with dynamic number

for ($i = 0; $i < count($json); $i++) {
    if ($i < 10) {
        $subtotalamount += floatval($json[$i]['amount_paid']);
    }
}

Short solution with range, array_slice and array_column functions:

// $arr is your initial array
$sub_totals = [];
foreach(range(0, count($arr), 10) as $k){
    $sub_totals[] = array_sum(array_column(array_slice($arr, $k, 10), 'amount_paid'));
}

• range(0, count($arr), 10) - generate an array containing a range of elements. It would be as [0, 10, 20]. Those elements are boundaries for each 10-sized sequence

• array_slice($arr, $k, 10) - each next boundary $k is used for extracting next 10-sized sequence/slice from the initial array $arr

$ret = array();
$subtotalamount = 0;
for ($i = 0; $i < count($json); $i++) {
    $subtotalamount += floatval($json[$i]['amount_paid']);
    if ($i % 10 == 9) {
        $ret[] = $subtotalamount;
        $subtotalamount = 0;
    }
}
if ($subtotalamount > 0) {
    $ret[] = $subtotalamount;
}

Easy to understand,You can use array_chunk(),array_sum(),array_column() like below:-

$new_array = array_chunk($array,10);
$sub_total_array = [];
foreach($new_array as $array){
   $sub_total_array[] = array_sum(array_column($array,'amount_paid'));
}
print_r($sub_total_array);

https://eval.in/876914

try this,

$sumofall = array();
for ($i = 0; $i < count($json); $i++) {
    if ($i % 10 == 0) {       
        $sumofeach = 0 
        for ($j=$i-10;$j<$i-1;$j++) {
            $sumofeach += floatval($json[$i]['amount_paid']);
        $sumofall[] = $sumofeach
    }
}

$a = array (0 => array ( 'amount_paid' => 2050.00 ), 1 => array ( 'amount_paid' => 2050.00 ) , 2 => array ( 'amount_paid' => 2050.00 ) , 3 => array ( 'amount_paid' => 2050.00 ) , 4 => array ( 'amount_paid' => 2050.00 ) , 5 => array ( 'amount_paid' => 2050.00 ) , 6 => array ( 'amount_paid' => 2050.00 ) , 7 => array ( 'amount_paid' => 2050.00 ) , 8 => array ( 'amount_paid' => 2050.00 ) , 9 => array ( 'amount_paid' => 2050.00 ) , 10 => array ( 'amount_paid' => 2050.00 ) , 11 => array ( 'amount_paid' => 2050.00 ) , 12 => array ( 'amount_paid' => 2050.00 ) , 13 => array ( 'amount_paid' => 2050.00 ) ) ; 

$b = array_column($a,'amount_paid');

$c = array_chunk($b,10);

$sum = [];
foreach($c as $arr){
    $sum[] = array_sum($arr);
}

echo "sum = ";
print_r($sum);