How to access Dictionary returned as JSON in JQuery?

Question

I have a controller method that returns a Dictionary to a JQuery ajax function:

public JsonResult GenerateLicensePlateSeries(string letters, int number, int amount)
{
    Dictionary<string, string> plates = new Dictionary<string, string>();

    var table = luxWebSamContext.LicensePlates;

    do
    {
        if (table.Where(x => x.LicensePlateNumber == (letters + number)).Count() == 0)
        {       
            plates.Add(letters + (number), "");
        }
        else
        {           
            plates.Add(letters + (number), table.Where(x => x.LicensePlateNumber == (letters + number)).Single().CommissionNumber);
        }

        number++;
    }
    while (plates.Count < amount);

    return Json(plates);
}

That code returns the following string:

{"AB2495":"","AB2496":"","AB2497":"","AB2498":"","AB2499":"","AB2500":"095753125"}

My problem is that i don't know how to access this data in the success function of my post method. I would like to iterate over the response and check if the second field of each key/pair value is populated with a number (the last one is):

$.post(baseUrl + '/de/SAM/GenerateLicensePlateSeries',
            {
                letters: $("#seriesLetters").val(),
                number: $("#seriesNumbers").val(),
                amount: $("#seriesAmount").val()
            },            
            function (returnedData) {

                var data = JSON.parse(returnedData);
                alert(data);
            });

I tried to parse it to JSON but i received an error:

Uncaught SyntaxError: Unexpected token o in JSON at position 1

Any ideas how to access the data?

When i print it to the console, it looks like this:

Have you tried to print the data without JSON.parse? For example just console.log(returnedData); ? — Nemanja Todorovic, Jun 09 '20 at 11:27
Note that `queryable.Where(lambda).Count() == 0` will almost always perform faster when written as `!queryable.Any(lambda)`. — Heretic Monkey, Jun 09 '20 at 13:11
Does this answer your question? [JSON parsing error - Unexpected token o in JSON at position 1](https://stackoverflow.com/questions/49033276/json-parsing-error-unexpected-token-o-in-json-at-position-1) — Heretic Monkey, Jun 09 '20 at 13:17
The reason for the error was that you were running `JSON.parse` on `returnedData`, which was not JSON, but an object that had already been parsed from the JSON. — Heretic Monkey, Jun 09 '20 at 13:23

score 0 · Answer 1 · answered Jun 09 '20 at 13:00

I have figured out the following workaround. I changed my data type from Dictionary to a list of anonymous types:

public JsonResult GenerateLicensePlateSeries(string letters, int number, int amount)
        {
            List<Object> plates = new List<Object>();            

            var table = luxWebSamContext.LicensePlates;            
            do
            {
                if (table.Where(x => x.LicensePlateNumber == (letters + number)).Count() == 0)
                {                    
                    var v = new 
                    { 
                        plate = letters + (number), 
                        assignedTo = "" 
                    };

                    plates.Add(v);
                }
                else
                {                 
                    var v = new 
                    { 
                        plate = letters + (number), 
                        assignedTo = table.Where(x => x.LicensePlateNumber == (letters + number)).Single().CommissionNumber
                    };
                    plates.Add(v);
            }

                number++;

            }
            while (plates.Count < amount);

            return Json(plates);
        }

Now my response looks like that:

And i can access it: in the ajax method:

success: function (returnedData) {                       



                for (var i = 0; i < returnedData.length; i++) {
                    alert(returnedData[i].plate);
                    alert(returnedData[i].assignedTo);
                }

            }

How to access Dictionary returned as JSON in JQuery?

1 Answers1