如何在具有最小值和组 PHP 的关联数组中逐一获取元素

Question

我有这样的关联数组

Array
(
    [0] => Array
        (
            [id] => 1,
            [product_uname] => AI 92
            [price_per_l] => 44.82
        )

    [1] => Array
        (
            [id] => 2
            [product_uname] => AI 95
            [price_per_l] => 46.43
        )

    [2] => Array
        (
            [id] => 3
            [product_uname] => AI 95
            [price_per_l] => 46.35
        )

    [3] => Array
        (
            [id] => 4
            [product_uname] => AI 92
            [price_per_l] => 44.19
        )

    [4] => Array
        (
            [id] => 5
            [product_uname] => AI 100
            [price_per_l] => 53.03
        )

)

我需要过滤数组，我们按 ['product_uname'] 字段分组，并在仅分组一个具有最低价格 [price_per_l] 字段的唯一元素后提取，并按 [[=21] 对数组排序=]] 字段之后，我需要查看

Array
(
    [0] => Array
        (
            [id] => 1
            [product_uname] => AI 92
            [price_per_l] => 44.19 (min value price where product_uname = AI 92)
        )

    [1] => Array
        (
            [id] => 2
            [product_uname] => AI 95
            [price_per_l] => 46.35 (min value price where product_uname = AI 95)
        )


    [2] => Array
        (
            [id] => 3
            [product_uname] => AI 100
            [price_per_l] => 53.03 (min value price because there is no any product_name = AI 100)
        )

)

是否可以不循环创建

Answer 1

我会这样做：

<?php
    $new_array = array();

    foreach($original_array as $key=>$item) {
      if(!isset($new_array[$item['product_uname']])) {
              //There isn't an item for this group in array, save this
            $new_array[$item['product_uname']] = $item;
      } else {
           if($new_array[$item['product_uname']]['price_per_l'] > $item['price_per_l']) {
              //If current item of group has higher price, replace it with this
              $new_array[$item['product_uname']] = $item;  
           }
      }
      
    }

Answer 2

如果您按 price_per_l 降序排序，然后按 product_uname 对数组进行索引，那么您将只得到最低的，因为后面的项目将取代前面的项目，而后面的项目价格最低：

array_multisort(array_column($array, 'price_per_l'), SORT_DESC, $array);
$array = array_column($array, null, 'product_uname');

如果需要，您可以重新编制索引：

$array = array_values($array);

Answer 3

$array = Array
(
    [0] => Array
        (
            [id] => 1,
            [product_uname] => AI 92
            [price_per_l] => 44.82
        )

    [1] => Array
        (
            [id] => 2
            [product_uname] => AI 95
            [price_per_l] => 46.43
        )

    [2] => Array
        (
            [id] => 3
            [product_uname] => AI 95
            [price_per_l] => 46.35
        )

    [3] => Array
        (
            [id] => 4
            [product_uname] => AI 92
            [price_per_l] => 44.19
        )

    [4] => Array
        (
            [id] => 5
            [product_uname] => AI 100
            [price_per_l] => 53.03
        )

);

array_multisort(array_column($array, 'price_per_l'), SORT_ASC, $array);
$array = array_column($array, null, 'product_uname');
$array = array_values($array);

如何在具有最小值和组 PHP 的关联数组中逐一获取元素

How to get one by one elements in associative array with min value and group PHP

php

arrays

associative-array