我正在处理一个购物车项目，有一个$_SESSION ['productSummary']数组，如下所示。

[productSummary] => Array
        (
            [0] => Array
                (
                    [name] => Individual Coins
                    [code] => 8774
                    [IDs] => Array
                        (
                            [0] => 8774
                            [1] => 8775
                            [2] => 8778
                            [3] => 8765
                        )

                    [pluID] => 6105
                    [qty] => 4
                    [finalPrice] => 0.0000
                    [listPrice] => 0.0000
                    [shipping] => 0.0000
                )

            [1] => Array
                (
                    [name] => Business Package - 5,000
                    [code] => 8770
                    [IDs] => Array
                        (
                            [0] => 8770
                        )

                    [pluID] => 6087
                    [qty] => 1
                    [finalPrice] => 125.0000
                    [listPrice] => 125.0000
                    [shipping] => 0.0000
                )

        )

当用户希望从购物车中删除商品#8778时，我需要找到“8778”的索引键值，以便从ID数组中删除该值。
这是我目前为止所拥有的代码片段。我为$matchingKey获得了很好的值，但是$matchingKey2总是空的。

// Find the key for the parent array
$matchingKey = array_search(8778, array_column($_SESSION["productSummary"], 'IDs'));

// Find the key for the element in the nested IDs array
$matchingKey2 = array_search(8778, array_column($_SESSION['productSummary'][$matchingKey]['IDs']));

// If it found a match, unset that element
if(!empty($matchingKey2)) {
     unset($_SESSION["productSummary"][$matchingKey]['IDs'][$matchingKey2]);
}

// Reindex the array
$_SESSION["productSummary"][$matchingKey]['IDs'] = array_values($_SESSION["productSummary"][$matchingKey]['IDs']);

我还以为

$matchingKey2 = array_search(8778, array_column($_SESSION['productSummary'][$matchingKey]['IDs']));

在本例中返回值2，但if返回NULL