jquery ajax returns list in the background, and uses jquery to traverse the list in the front desk

As shown below:

   
$.ajax({ 
    type: 'post', 
    url: "maintain_findRoomByBuildingId.shtml", 
    cache: false, 
    data: {"buildingId":buildingId}, 
    dataType: 'json', 
    success: function(data){ 
      jQuery.each(data.roomList, function(i,item){ 
        alert(item.id+","+item.name); 
      }); 
    }, 
    error: function(){ 
      return; 
    } 
  });