TypeError Obj.root是未定义的Ajax jQuery

Question

I am getting a console log output saying TypeError: treeObj.root is undefined on this line: var count = treeObj.root.length; not sure why or how to solve it?

   $.ajax({
        url: 'Content/data.txt',
        dataType: 'text',
        success: function (treeObj) {

            var count = treeObj.root.length; //here

Answer 1

with dataType: 'text' you tell the ajax-call to treat the answer from the server as a plain string. Try changing that to dataType: 'json'

Answer 2

treeObj is most likely getting passed in as a string, not an object so you need to parse the string into an object using something along:

try{
   treeObj = jQuery.parseJSON(treeObj);
}catch(e){}