json string to object with array

Question

var test = {'abc':76,'data':'[6435,3310,56.06875]'}

how do I convert above json string to an object say:

class item
{
    public string abc {Get;set;}
    public float[] data {get;set}
}

I tried JsonConvert.DeserializeObject<item>(test); but get this error:

{"Error converting value \"[6435,3310]\" to type 'System.Single[]'. Path 'data', line 1, position 117."}

http://stackoverflow.com/questions/6620165/how-can-i-parse-json-with-c — Jacob Brazeal, Jan 11 '17 at 04:09
Possible duplicate of [How can I parse JSON with C#?](http://stackoverflow.com/questions/6620165/how-can-i-parse-json-with-c) — Daniel Mann, Jan 11 '17 at 04:13
OK, I find that it is because i have '[x,x,x]' instead of [] — Zhongmin, Jan 11 '17 at 04:20
Hello @Zhongmin have a look at the solution provided by me and acknowledge if that works for you. :) — Mohit S, Jan 13 '17 at 01:30

score 0 · Accepted Answer · answered Jan 11 '17 at 04:46

There are a few problems with the json string (i am assuming you are using C#). First of the values of the data property are actually a string (given the quotes). Which is why you are getting the error.

What you could do is create a property to hold the string and then another property to parse the float values after parsed. This is done by using a few JSON.Net attributes of JsonProperty and JsonIgnore. These attributes tell the serializer what the property name is in the json string and which properties to ignore.

class Foo
{
    string dataString;
    float[] data = null;

    [JsonProperty("abc")]
    public string Abc { get; set; }

    [JsonProperty("data")]
    public string DataString
    {
        get { return dataString; }
        set
        {
            data = null;
            dataString = value;
        }
    }

    [JsonIgnore]
    public float[] Data
    {
        get
        {
            if (data != null)
                return data;

            return data = dataString != null ? JsonConvert.DeserializeObject<float[]>(DataString) : null;
        }
        set
        {
            DataString = value == null ? null : JsonConvert.SerializeObject(value);
        }
    }
}

This looks like alot of code however uses backing fields to allow you to change both the Data field and the DataString field while maintaining a working serializer.

This is then simply called using

var i = JsonConvert.DeserializeObject<Foo>(test);

score 0 · Answer 2 · answered Jan 11 '17 at 10:03

This might do the trick for you

string jsn = @"{'abc':76,'data':'[6435,3310,56.06875]'}";
jsn = jsn.Replace("'[", "[");
jsn = jsn.Replace("]'", "]");
var ser = JsonConvert.DeserializeObject<ClsResult>(jsn);

I have used replace because 'data':'[6435,3310,56.06875]' is making the array of data to string. So better we make it like 'data':[6435,3310,56.06875] and then you class would look like

public class ClsResult
{
    [JsonProperty("abc")]
    public int abc { get; set; }

    [JsonProperty("data")]
    public IList<double> data { get; set; }
}

json string to object with array

2 Answers2