我该如何简化这个数组呢？

Question

我有这个数组:

Array
(
    [0] => Array
        (
            [tag_id] => 1
        )

    [2] => Array
        (
            [tag_id] => 3
        )

    [22] => Array
        (
            [tag_id] => 44
        )

    [23] => Array
        (
            [tag_id] => 45
        )

    [25] => Array
        (
            [tag_id] => 47
        )

    [26] => Array
        (
            [tag_id] => 48
        )

)

我希望它看起来像这样,所以我更简单地循环并将每个值插入数据库:

Array
(
    [0] => 1
    [1] => 3
    [2] => 44
    [3] => 45
    [4] => 47
    [5] => 48
)

Answer 1

您可以使用array_map.

PHP 5.3或更高版本:

$callback = function($value) {
   return $value['tag_id'];
};
$result = array_map($callback, $array);

5.3以下:

function collapseTagIds($value) {
  return $value['tag_id'];
}
$result = array_map('collapseTagIds', $array);