Question

$array看起来像这样。

Array
 (
     [CategoryID] => 4352
     [CategoryLevel] => 3
     [CategoryName] => Tags
 )

Array
 (
     [CategoryID] => 3243
     [CategoryLevel] => 2
     [CategoryName] => Actions
 )

Array
 (
     [CategoryID] => 2342
     [CategoryLevel] => 3
     [CategoryName] => Tags
 )

等等。

我尝试过foreach循环

$newarray = array();
foreach ($array as $key => $value) {
    $categorylevel = $value['CategoryLevel'];
    $newarray[][$categorylevel] = $categorylevel;
}

但是输出看起来像这样：

Array
(
    [0] => Array
        (
            [3] => 4352
        )

    [1] => Array
        (
            [2] => 3243
        )

    [2] => Array
        (
            [3] => 2342
        )
        . . . . . . . .

而不是我想要的输出

Array
(
    [2] => Array
        (
            [0] => 3243
        )

    [3] => Array
        (
            [0] => 4352
            [0] => 2342
        )
        . . . . . . . .

如何修改foreach代码以产生所需的输出？

Simply putting it in the $newarray key only brings back the last iterations of the Category Levels value

$newarray = array();
foreach ($array as $key => $value) {
    $categorylevel = $value['CategoryLevel'];
    $newarray[$categorylevel] = $categorylevel;
}

输出：

. . . . . . . .
. . . . . . . .
[4] => 5967
[5] => 6756
[6] => 9933
)

Answer 1

您有一个非常简单的错误。这行是错误的。

$newarray[][$categorylevel] = $categorylevel;

它应该是：

$newarray[$categorylevel][] = $value['CategoryID'];

基于多维数组级别创建数组

1 个答案: