JSON values parsed as undefined in javascript

Question

I am trying to parse a JSON in Javascript. The JSON is created as an ajax response:

$.ajax(url, {
  dataType: "text",
  success: function(rawData, status, xhr) {
    var data;
    try {
      data = $.parseJSON(rawData);
      var counter = data.counter;
      for(var i=1; i<=counter; i++){
        //since the number of 'testPath' elements in the JSON depend on the 'counter' variable, I am parsing it in this way
        //counter has the correct integer value and loops runs fine
        var currCounter = 'testPath'+i ;
        alert(data.currCounter); // everything alerts as undefined
      }
    } catch(err) {
      alert(err);
    }
  },
  error: function(xhr, status, err) {
    alert(err);
  }
});

But all values alert 'undefined' as value (except the 'counter' which gives correct value) The actual string as seen in firebug is as below:

{"testPath1":"ab/csd/sasa", "testPath2":"asa/fdfd/ghfgfg", "testPath3":"ssdsd/sdsd/sds", "counter":3}

why don't you use `dataType` as `JSON` and send response as `JSON` instead of `text` ?? — bipen, Jun 04 '13 at 06:58

score 15 · Accepted Answer · answered Jun 04 '13 at 07:00

15

alert(data[currCounter]) , this will work.

as data.currCounter looks for the key 'currCounter` in the object, not by the value of currCounter.

example:

http://jsfiddle.net/bJeWm/1/

var myObj = { 'name':'dhruv','age':28 };
var theKey = 'age';
alert(myObj.theKey);  // undefined
alert(myObj[theKey]); // 28

answered Jun 04 '13 at 07:00

DhruvPathak

42,059
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Thanks @DhruvPathak .. It just worked by using [] instead of "." – Riju Mahna Jun 04 '13 at 07:14

score 3 · Answer 2 · edited Jun 04 '13 at 07:02

3

Use

alert(data[currCounter]);

instead. You cannot access a property like you did....

edited Jun 04 '13 at 07:02

bipen

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answered Jun 04 '13 at 07:01

sjkm

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score 2 · Answer 3 · answered Jun 04 '13 at 07:01

2

Need to use [] notation

data[currCounter]

answered Jun 04 '13 at 07:01

Sushanth --

55,259
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score 1 · Answer 4 · answered Jun 04 '13 at 07:02

1

Try data[currCounter] because there is no value in data.currCount.

answered Jun 04 '13 at 07:02

user2059250

63
5

JSON values parsed as undefined in javascript

4 Answers4