Why is my JavaScriptSerializer returning empty json objects?

Question

I have a list of data points, as defined below:

public class Point {
    string Rate;
    string Date;
    string Number;

    public Point(string Rate, string Date, string Number)
    {
        this.Rate = Rate;
        this.Date = Date;
        this.Number = Number;
    }
}

Then within my code I have:

List<Point> points = populatedList;
JavaScriptSerializer javaScriptSerializer = new JavaScriptSerializer();

string text = javaScriptSerializer.Serialize(points);

System.IO.File.WriteAllText(@"C:\Users\Public\WriteText.txt", text);

When I go to view "WriteText.txt", however, all I have is a bunch of empty brackets: {}, {}, {} ... I have also tried doing this with only one point, and then I am left with only one matching pair of brackets. I then tried serializing a string object alone and that worked fine. Why is the JavaScriptSerializer not behaving as expected?

Do you perhaps mean to serialize `points` and not `toSerialize`? — User 12345678, Jul 25 '14 at 21:30
Yes, my mistake, actual code has JsonSerialization as a separate method — mike, Jul 25 '14 at 21:31

Travis J · Accepted Answer · 2014-07-25T21:49:09.500

17

The access level for class members and struct members, including nested classes and structs, is private by default. - Access Modifiers^MSDN

As a result of that, the serialization will not see those properties. In order for them to be serialized, they need to be marked as public. They also need to have a public getter in order for the serializer to read the property.

public string Rate { get; set; }
public string Date { get; set; }
public string Number { get; set; }

edited Jul 25 '14 at 21:49

answered Jul 25 '14 at 21:32

Travis J

81,153
41
202
273

I've only started using C# recently, I am used to Java where I've gotten used to private access modifiers and public getters / setters. It seems like C# likes public access modifiers for class variables; is there a reason for this? – mike Jul 28 '14 at 15:21
@mike - It doesn't have to be like that, you could use `public { get; }` instead. As for design decisions for property exposure, I think that is language agnostic. – Travis J Jul 28 '14 at 18:20
While I agree, the examples provided by the official docs of a given language definitely seem to promote some tendencies... – mike Jul 28 '14 at 18:27
@mike - That is basically a result of just making a simple example. Most of those are bare bones examples and only include properties which are going to be used so they must be exposed. Moreover, any example which is shown using an ORM is going to be using public getter and setter properties in order to faciliate database persistence. If you have a specific example in mind and are wondering why there is a public property which you think should be private, feel free to link it. – Travis J Jul 28 '14 at 18:44
The ORM comment pretty much answers it for me – mike Jul 28 '14 at 18:52

Why is my JavaScriptSerializer returning empty json objects?

1 Answers1

Linked