- var_dump: documentation ( source)
- array_intersect_key: documentation ( source)
- array_sum: documentation ( source)
- array_intersect: documentation ( source)
- array_column: documentation ( source)
- array_unique: documentation ( source)
<?php
$arr=array(
Array
(
0 => 3,
1 => 1
),
Array
(
0 => 3,
1 => 2
),
Array
(
0 => 3,
1 => 128
),
Array
(
0 => 39,
1 => 4
));
$col0 = array_unique(array_column($arr, 0));
Foreach($col0 as $val){
// $res[] = [$val,
Var_dump(array_sum(array_intersect_key($arr, array_intersect($col0, [$val]))));
}
Var_dump($res);