php数组到ajax var

I have an opensliding side panel in wich I display content. I have a working example, but it works on an ajax var that I've put in. I would like to scan a folder for the files loaded in my ajax code. How can I pass folder content into my ajax?

PHP

    <div class="standorte-wrapper">
      <div class="panel left"><!-- start pannel left -->
         <div class="pan-item tl">
           <button  class="show-hide" data-ajaxFile="0">OPEN</button>
         </div> 
         <div class="pan-item tr">
           <button  class="show-hide" data-ajaxFile="1">OPEN</button>
         </div>
         <div class="pan-item bl">
           <button  class="show-hide" data-ajaxFile="2">OPEN</button>
         </div>
         <div class="pan-item br">
           <button  class="show-hide" data-ajaxFile="3">OPEN</button>
         </div>
      </div><!-- end pannel left -->
      <div id="open" class="panel right"><!-- start sliding pannel right -->
         <div class="close-button">
           <a href="#" id="close" class="close">close</a>
         </div>
         <div id="content">
           <div id="php-content"></div>
         </div>
       </div>
   </div>

AJAX

    $(document).ready(function() {

      var ajaxUrls = [
        '/standorteContent/brauerstrasse.php',
        '/standorteContent/gutterstrasse.php',
        '/standorteContent/kauffmannweg.php',
        '/standorteContent/konradstrasse.php'
      ];

      var ajaxFiles = [];

     for (var i = 0; i < ajaxUrls.length; i++) {
       $.ajax({
          method: 'GET',
          url: ajaxUrls[i],
          success: function(data) {
          //console.log(data);
          ajaxFiles.push(data);
       }
      });
    }
    $('.adres-wrap > button').on('click', function() {
      if ($('.panel.left').hasClass('open')) {
        //alert('already open');
       } else {
       $('.panel.left').addClass('open', 1000, "easeInBack");
       $('.standorte-wrapper').addClass('expand');
       }

     $('#php-content').html(ajaxFiles[$(this).attr('data-ajaxFile')]);
     setTimeout(function (){
       $('.panel.right div').fadeIn(400);
     }, 500);   
    });

    $('#close').on('click', function() {
        $('.panel.right div').fadeOut(400);
        setTimeout(function (){
           $('.panel.left').removeClass('open');
           $('.standorte-wrapper').removeClass('expand');
        }, 500);
     });
    });

LOOKS LIKE

QUESTION

How can I change so that I don't have to add data-ajaxFile="nr" manual for every button? And I would like ajaxUrls get the path for php files only in a directory on my server. Can anyone help me out on this one?