php - Array reorganization help~~

Question

The following arrays have the same gid and require Num to be accumulated. Those with different gid are displayed directly without any operation. How to achieve array deduplication? {code...}

怪我咯 · Answer

     $arr = array(
                array(
                        'gid' => 1,
                        'num' => 4,
                    ),
                array(
                        'gid' => 1,
                        'num' => 4,
                    ),
                array(
                        'gid' => 3,
                        'num' => 3,
                    ),
                array(
                        'gid' => 4,
                        'num' => 4,
                    ),
         );
    
    $result = array();
    foreach($arr as $val) {
        if(!isset($result[$val['gid']])) {
            $result[$val['gid']] = $val;
            continue;
        }
        
        $result[$val['gid']]['num'] += $val['num'];
    }
    
    var_dump("", $result);die;

滿天的星座 · Answer

You found this out from the data in the database, right? If so, directly use the sql statement to deduplicate the gid, and then use sum() to accumulate the num, and you can get the result.

習慣沉默 · Answer

$ret = [['gid' => 2,'num' => 5],['gid' => 3,'num' => 5],['gid' => 2,'num' => 6]];
$newret = array();
foreach($ret as $key => $val){
    $newret[$val['gid']]['gid'] = $val['gid'];
    $newret[$val['gid']]['num'] += $val['num'];
}
sort($newret);


//结果
Array
(
    [0] => Array
        (
            [gid] => 2
            [num] => 11
        )
    [1] => Array
        (
            [gid] => 3
            [num] => 5
        )
)