在PHP中使用自定义ID格式化数组树

Question

I have an array I need formatted into a single array. The current function I have works well aside for I can't figure out how to set a custom key for the ID. The array is used to populate a select box, so I need that ID. I spent hours messing with it and I am just lost when it comes to formatting arrays.

I need the output to use a custom key (eg. $row->id ) which would output something like:

[40 =>'Florida', 50 =>'CA', 33 => 'NY']

Right now it outputting like..

[0 =>'Florida', 1 =>'CA', 2 => 'NY']

This is my current function:

protected function createRegionList($parent_id = '0', $spacing = '')
{

    $arr = [];
    foreach ($this->getByParentId($parent_id) as $row) {
        $arr[] = $spacing . ' ' . $row->title;
        $arr = array_merge($arr, $this->createRegionList($row->id, ' ' . $spacing . '—'));
    }
    return $arr;

}

Any help or suggestion would be much appreciated. I have found a bunch of examples, but they are more multidimensional arrays and I need the output as a single array.

Answer 1

You can set array item key by specifying the key in brackets. See PHP docs.

Try this

$arr[$row->id] = $spacing . ' ' . $row->title;

array_merge is not preserving keys. Use array_replace.

Or just union these together

$arr = [];
foreach ($this->getByParentId($parent_id) as $row) {
    $arr[] = $spacing . ' ' . $row->title;
    $childs = $this->createRegionList($row->id, ' ' . $spacing . '—');
    $arr = $childs + $arr;
}
return $arr;