PHP对某个索引相同的多维数组值求和答案

【问题标题】：PHP Sum multidimensional array values where certain index is the samePHP对某个索引相同的多维数组值求和
【发布时间】：2020-07-08 17:33:37
【问题描述】：

这里只是一个简单的问题。我有以下数组：

Array(21) {
[0] => Array(7) {
    ["punti"] => Integer  418
    ["vittorie"] => Integer  9
    ["podi"] => Integer  18
    ["gv"] => Integer  14
    ["id_pilota"] => Integer  1
    ["team"] => String(15) "Red Bull Racing"
    ["naz"] => String(2) "it"
}
[1] => Array(7) {
    ["punti"] => Integer  353
    ["vittorie"] => Integer  6
    ["podi"] => Integer  16
    ["gv"] => Integer  3
    ["id_pilota"] => Integer  19
    ["team"] => String(16) "Scuderia Ferrari"
    ["naz"] => String(2) "it"
}
[2] => Array(7) {
    ["punti"] => Integer  335
    ["vittorie"] => Integer  4
    ["podi"] => Integer  15
    ["gv"] => Integer  1
    ["id_pilota"] => Integer  5
    ["team"] => String(12) "Mercedes-AMG"
    ["naz"] => String(2) "it"
}
[3] => Array(7) {
    ["punti"] => Integer  181
    ["vittorie"] => Integer  1
    ["podi"] => Integer  5
    ["gv"] => Integer  1
    ["id_pilota"] => Integer  2
    ["team"] => String(12) "Mercedes-AMG"
    ["naz"] => String(2) "it"
}
[4] => Array(7) {
    ["punti"] => Integer  147
    ["vittorie"] => Integer  0
    ["podi"] => Integer  3
    ["gv"] => Integer  0
    ["id_pilota"] => Integer  14
    ["team"] => String(15) "Racing Point F1"
    ["naz"] => String(2) "mx"
}
[5] => Array(7) {
    ["punti"] => Integer  127
    ["vittorie"] => Integer  0
    ["podi"] => Integer  0
    ["gv"] => Integer  0
    ["id_pilota"] => Integer  13
    ["team"] => String(7) "Haas F1"
    ["naz"] => String(2) "dk"
}

减少到 21 个元素。

我的目标是根据每个飞行员的团队总结所有分数（“punti”索引）。所以要获得这样的东西：

Array(10) {
[0] => Array(2) {
    ["team"] => String(...) "Mercedes-AMG")
    ["points"] => Integer  516

我知道这很容易，但是解决此类问题的最快/最方便的方法是什么？

【问题讨论】：

标签： php arrays multidimensional-array sum key

【解决方案1】：

应该像下面这样：

function sum_teams($arr = []) {
    // array for final results
    $collection = [];

    foreach ($arr as $item) {
        $keys = array_keys($item);

        foreach ($keys as $key) {
            $value = $item[$key];

            // check if we captured the key already
            if ($collection[$key]) {
                // increment up by current value
                $collection[$key] += $value;
            } else {
                // set to current value
                $collection[$key] = $value;
            }
        }
    }
    return $collection;
}
// call it with your array
$result = sum_teams($some_array);
printr_r($result);

【讨论】：

工作正常，但我正在寻找更紧凑的解决方案。不过感谢您的帮助。

【解决方案2】：

您需要对结果进行迭代，在遇到新团队时向输出添加新条目，或者在再次找到同一团队时更新积分值。这最容易通过最初按团队名称索引输出，然后使用array_values 以数字方式重新索引数组来完成：

$teams = array();
foreach ($results as $result) {
    $team = $result['team'];
    if (!isset($teams[$team])) {
        $teams[$team] = array('team' => $team, 'points' => $result['punti']);
    }
    else {
        $teams[$team]['points'] += $result['punti'];
    }
}
$teams = array_values($teams);
print_r($teams);

输出（用于您的样本数据）：

Array
(
    [0] => Array
        (
            [team] => Red Bull Racing
            [points] => 418
        )
    [1] => Array
        (
            [team] => Scuderia Ferrari
            [points] => 353
        )
    [2] => Array
        (
            [team] => Mercedes-AMG
            [points] => 516
        )
    [3] => Array
        (
            [team] => Racing Point F1
            [points] => 147
        )
    [4] => Array
        (
            [team] => Haas F1
            [points] => 127
        )
)

Demo on 3v4l.org

【讨论】：

@GiovanniRizza 不用担心——我很高兴能帮上忙。