PHP如何在二维数组获取上一级键值？

Question

数组：

Array(
    [hello] => Array
        (
            [0] => config.php
            [1] => install.txt
        )

    [js01] => Array
        (
            [0] => config.php
            [1] => install.txt
        )

    [js02] => Array
        (
            [0] => config.php
        )

)

PHP代码：

$path = 上面数组;

foreach($path as $k=>$v){
    //新增file_name  
    //key 这个只能获取 0 
    $path[$k]['file_name'] = key($path[$k]);
    
}
print_r($path);

我想实现 在file_name值获取到一维的键值，效果如下：

Array(
    [hello] => Array
        (
            [0] => config.php
            [1] => install.txt
            [file_name] => hello
        )

    [js01] => Array
        (
            [0] => config.php
            [1] => install.txt
            [file_name] => js01
        )

    [js02] => Array
        (
            [0] => config.php
            [file_name] => js02
        )

)

如何实现？

Answer 1

array_walk($path, function (&$value, $key) {
            $value['file_name'] = $key;
        });