Question

{
  'lastChangedName': null'Caption': 'Adhesive Tape',
  'CreateByID': 0,
  'DateOnSet': '02/10/2011',
  'Note': 'Currently participating in Allergy shots to resolve this',
  'Reaction': 'skin rash',
  'SectionDescription': 'Allergy List',
  'HistoryItemID': 1831,
  'CurrentInDrFirst': 0,
  'CreateDate': '/Date(1297674300000-0500)/',
  'Code': '3746',
  'PL': '1',
  'Problem': {
    "LastChargedByUserID": 0,
    "LastChargedDate": null,
    "ProblemStatus": 1003,
    "DateResolved": "12\/2\/11",
    "PatientID": 0,
    "ProblemID": 1330
  },
  'CategoryDescription': null,
  'CategoryID': 0,
  'CodeSystem': 'FDBDRUG',
  'SectionID': 3,
  'LastChangedID': 0,

},
{
  'lastChangedName': null'Caption': 'Cats',
  'CreateByID': 0,
  'DateOnSet': '6/4/1997',
  'Note': '0',
  'Reaction': 'Sneezing',
  'SectionDescription': 'Allergy List',
  'HistoryItemID': 1925,
  'CurrentInDrFirst': 0,
  'CreateDate': '/Date(1299176220000-0500)/',
  'Code': '',
  'PL': '1',
  'Problem': {
    "LastChargedByUserID": 0,
    "LastChargedDate": null,
    "ProblemStatus": 1002,
    "DateResolved": null,
    "PatientID": 0,
    "ProblemID": 1331
  },
  'CategoryDescription': null,
  'CategoryID': 0,
  'CodeSystem': '',
  'SectionID': 3,
  'LastChangedID': 0,

}

This is the response i get, i want to iterate and print out the caption values… in a text box…

for each(var item in response) {
          alert(item.caption)
}

This only prints me the first caption alone.

Answer 1

That response, as quoted, is awkward because you have a series of anonymous objects separated by commas (you might think it was invalid, but it’s not, it’s just unhelpful). (That’s assuming you fix the 'lastChangedName': null'Caption' thing that symcbean pointed out in the comments; I assume that’s a copy-and-paste error.) I think there must be more to it than what’s quoted. (Is it, perhaps, inside [ and ], making it an array of objects?)

But generally speaking: Yes, for..in (not for each, just for) is used to loop through the names of the properties of an object, and once you have each name, you can use [] notation to retrieve the property value.

So if you can get a reference to each of those objects, you can use for..in to loop through the properties.

Example:

var obj, name;

obj = {
    foo: "bar",
    answer: 42
};

for (name in obj) {
    console.log(name + ": " + obj[name]);
}

That will show

foo: bar
answer: 42

or

answer: 42
foo: bar

The order of the property names in the loop is not specified for generic objects like those in your example. (It’s specified for Array objects: With Array objects it’s guaranteed that any properties they have with purely numeric names — e.g., array indexes — will be iterated in numeric order. [Even then, if you have non-numeric properties on the array as well, it’s undefined whether those will be before, after, or intermixed with, the numeric ones.])