从foreach循环php构建树

Question

我有以下foreach循环：

foreach($mydata as $data){
    $section = $data->section;
    $category = $data->category;
    $item = $data->item;
}

我想像这样构建树：

- section
    _ category
        - items
...

现在我确实喜欢这个：

$tmp = [];
$newarray = [];
foreach($mydata as $data){
    $section = $data->section;
    $category = $data->category;
    $item = $data->item;
    if( !in_array($category, $temp)){
        $newarray[$section][] = $category;
    } 
}

// output:
Array(
    [SectionName_one] => Array(
        [0] => categoryOneName_one
        [1] => categoryOneName_two
        [2] => categoryOneName_three
    )
    [SectionName_two] => Array(
        [0] => categoryTwoName_one
        [1] => categoryTwoName_two
        [2] => categoryTwoName_three
    )
    ...
)

我在这里被封锁，我不知道如何为每个类别插入项目元素，如果你有一个想法感谢帮助我：）

谢谢

Answer 1

foreach ($mydata as $data){
    $newarray[$data->section][$data->category][]= $data->item;
}

PHP对于不存在的数组键非常宽容。