多維數組的過濾器部分

Question

我想過濾多維數組的一部分。 我已經使用了array_filter函數。 當我打印過濾后的數據時，它可以正確顯示，但是似乎無法將數據保存回陣列中。

這是預先的多維數組（稱為$posted_product_details ），其中包含我想要過濾的內部數組（ [data] ）：

Array
(
[column_1] => Array
    (
        [name] => Colour
        [data] => Array
            (
                [0] => Blue
                [1] => Green
                [2] => Red
                [3] => Yellow
                [4] => 
                [5] => 
                [6] => 
                [7] => 
                [8] => 
                [9] => 
            )

    )

[column_2] => Array
    (
        [name] => Pack QTY
        [data] => Array
            (
                [0] => 3
                [1] => 3
                [2] => 3
                [3] => 3
                [4] => 
                [5] => 
                [6] => 
                [7] => 
                [8] => 
                [9] => 
            )

    )

[column_3] => Array
    (
        [name] => Product Code
        [data] => Array
            (
                [0] => 65030
                [1] => 65029
                [2] => 65028
                [3] => 65031
                [4] => 
                [5] => 
                [6] => 
                [7] => 
                [8] => 
                [9] => 
            )

    )

[column_4] => Array
    (
        [name] => Barcode
        [data] => Array
            (
                [0] => 5099570650307
                [1] => 5099570650291
                [2] => 5099570650284
                [3] => 5099570650314
                [4] => 
                [5] => 
                [6] => 
                [7] => 
                [8] => 
                [9] => 
            )

    )

[column_5] => Array
    (
        [name] => 
        [data] => Array
            (
                [0] => 
                [1] => 
                [2] => 
                [3] => 
                [4] => 
                [5] => 
                [6] => 
                [7] => 
                [8] => 
                [9] => 
            )

    )

)

在這里，我嘗試遍歷數組並過濾數據：

foreach ($posted_product_details as $column => $info) {
    $name = $info['name'];
    $data = $info['data'];
    $info['data'] = array_filter($data);
}

但是，在隨后打印陣列時，該陣列沒有更改。

Answer 1

通過引用傳遞值以修改原始數組：

foreach ($posted_product_details as $column => & $info) {
    $name = $info['name'];
    $data = $info['data'];
    $info['data'] = array_filter($data);
}

這將正確過濾數組的data部分。 但是，如果您需要過濾掉更深層的元素，則必須使用一個遞歸函數，例如this 。

演示！

Answer 2

在遍歷數組時，foreach構造會復制數組的每個部分。 您必須顯式調用原始數組進行編輯：

$posted_product_details[$column]['data'] = array_filter($data);