Question

Here variable data should hold the data getJSON-method returns. But is there something wrong? It seems the data is empty.

$(function(){
$("#subjectgroups").change(function(){


  $.getJSON("/getSubCategories?id="+$("#subjectgroups").val(), function(data){
  var options = '';
  for (var i = 0; i < data.length; i++) {
    options += '<option value="' + data[i].id + '">' + data[i].description + '</option>';
  }
  $("#mainsubjects").html(options);

})
});
});

When I type the getJSON url on browser, I get the json elements just right, example:

  [{"description":"Religion","id":34},{"description":"uskonto","id":9}] 

Answer 1

remove the comma in "/getSubCategories?id=",+$("#subjectgroups").val()