在 PHP 中通过对多维数组进行分组来计数

2021-12-30 00:00:00 grouping count php

可能的重复:
php 如何按特定的对象对多维数组进行分组价值?
php 使用多维数组按 SUM 分组

我需要一些帮助来获取数组元素数量的计数，方法是根据 php 中多维数组的日期值部分对其进行分组

I need some help in getting the count of the array element quantity by grouping it based on a date value part of a Multidimensional array in php

这是我的原始数组

Array
(
[0] => Array
    (
        [quantity] => 5
        [dd] => 01-Nov-2012
    )

[1] => Array
    (
        [quantity] => 10
        [dd] => 01-Nov-2012
    )

[2] => Array
    (
        [quantity] => 3
        [dd] => 02-Nov-2012
    )

[3] => Array
    (
        [quantity] => 4
        [dd] => 03-Nov-2012
    )

[3] => Array
    (
        [quantity] => 15
        [dd] => 03-Nov-2012
    )
)

这是我期待的输出

Array
(
[0] => Array
    (
        [quantity] => 15
        [dd] => 01-Nov-2012
    )

[1] => Array
    (
        [quantity] => 3
        [dd] => 02-Nov-2012
    )

[2] => Array
    (
        [quantity] => 19
        [dd] => 03-Nov-2012
    )
)

推荐答案

只需遍历行，然后将不同数组中的数量相加，这些数组由 dd 值索引.

Just loop trough the rows, and add up the quantities in a different array indexed by the dd values.

$in = array(array()); // your input
$out = array();
foreach ($in as $row) {
    if (!isset($out[$row['dd']])) {
        $out[$row['dd']] = array(
            'dd' => $row['dd'],
            'quantity' => 0,
        );
    }
    $out[$row['dd']]['quantity'] += $row['quantity'];
}
$out = array_values($out); // make the out array numerically indexed
var_dump($out);

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