如何在多維數組中按鍵搜索

Question

如何在多維數組中按鍵[sub1]的值進行搜索並顯示印象數和收益。 數組行可以有無限的國家。

Array
(
    [rows] => Array
        (
            [0] => Array
                (
                    [sub1] => Spain
                    [impressions] => 1022
                    [earnings] => 0.13
                )

            [1] => Array
                (
                    [sub1] => Germany
                    [impressions] => 801
                    [earnings] => 0.01
                )

            [2] => Array
                (
                    [sub1] => Italy
                    [impressions] => 684
                    [earnings] => 0.35
                )
        )       
)

Answer 1

如果sub1是唯一的，那么只需重新索引即可，然后使用國家/地區即可輕松訪問它：

$lookup = array_column($array['rows'], null, 'sub1');
echo $lookup['Italy']['impressions'];

也許先測試一個有效的國家：

if(isset($lookup['Italy'])) {
    echo $lookup['Italy']['impressions'];
}