<?php
$array = [
[
'tag_id' => "6291",
'az' => 5,
],
[
'tag_id' => "6291",
'az' => 4,
],
[
'tag_id' => "6311",
'az' => 4,
],
[
'tag_id' => "6427",
'az' => 4,
]
];
$res = array_reduce(
$array,
function($ac, $el) {
$ac[$el['tag_id']] += $el['az'];
return $ac;
},
[]
);
print_r($res);
$res = array_map(
fn($k, $v) => ['tag_id' => $k, 'az' => $v],
array_keys($res),
$res
);
print_r($res);