如何获取所有文件目录和子目录名称作为php中的json对象

Question

我正在尝试将所有目录和子目录列表作为JSON对象获取，但是我对如何执行此操作没有任何想法。

目前我正在这样阅读

->test.php 

$path = realpath('Question Papers');
$self_files = glob($path . '/*');
$recursive_files = glob($path . '/**/*');

$all_files = $self_files + $recursive_files;
echo json_encode($all_files);

-> output on my js page 

JS: C:\xampp\htdocs\projects\Question Papers/2014.pdf
JS: C:\xampp\htdocs\projects\Question Papers/2015.pdf
JS: C:\xampp\htdocs\projects\Question Papers/2016.pdf
JS: C:\xampp\htdocs\projects\Question Papers/2017.pdf
JS: C:\xampp\htdocs\projects\Question Papers/2018.pdf
JS: C:\xampp\htdocs\projects\Question Papers/Aeronautical
JS: C:\xampp\htdocs\projects\Question Papers/Civil
JS: C:\xampp\htdocs\projects\Question Papers/Electrical
JS: C:\xampp\htdocs\projects\Question Papers/Civil/2017.pdf
JS: C:\xampp\htdocs\projects\Question Papers/Civil/2018.pdf
JS: C:\xampp\htdocs\projects\Question Papers/Electrical/2014.pdf
JS: C:\xampp\htdocs\projects\Question Papers/Electrical/2015.pdf
JS: C:\xampp\htdocs\projects\Question Papers/Electrical/2016.pdf
JS: C:\xampp\htdocs\projects\Question Papers/Electrical/2017.pdf
JS: C:\xampp\htdocs\projects\Question Papers/Electrical/2018.pdf

我期待下面的事情

Question Papers {
       Civil{2014.pdf,2015.pdf,2016.pdf,2017.pdf,2018.pdf},
       Electrical{2014.pdf,2015.pdf,2016.pdf,2017.pdf,2018.pdf},
       Aeronautical{2014.pdf,2015.pdf,2016.pdf,2017.pdf,2018.pdf}
}

任何人都可以帮助我如何在php或javascript中实现这一目标。